diff --git a/examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs b/examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs
index 26e30425..7ebd273d 100644
--- a/examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs
+++ b/examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs
@@ -160,9 +160,6 @@ private void OnSendCatalogueEvent(EventSpec spec, Dictionary<string, VisualEleme
                 }, 2);
             });
 
-        // SDK drops via Log.Warn when name is empty or consent is None; that
-        // warning surfaces in the pane via Log.Writer, so no sample-side
-        // check is needed beyond GuardConsentForTrack.
         private void OnSendCustomEvent() => RunAndLog("track()", () =>
         {
             GuardConsentForTrack();
@@ -205,10 +202,10 @@ private void OnIdentify() => RunAndLog("identify()", () =>
             var f = CaptureIdentifyForm();
             var traits = ParseTraits(f.RawTraits);
             ImmutableAudience.Identify(f.Id, ParseIdentityType(f.Type), traits);
-            // SDK drops via Log.Warn when id is empty or consent < Full. Mirror
-            // only when accepted; otherwise the panel would show stale state.
-            var accepted = !string.IsNullOrEmpty(f.Id)
-                           && string.Equals(ImmutableAudience.UserId, f.Id, StringComparison.Ordinal);
+            // Empty ids and malformed passport ids throw, caught by RunAndLog
+            // before this line runs. The one silent no-op left is consent
+            // below Full, which the UserId check below still catches.
+            var accepted = string.Equals(ImmutableAudience.UserId, f.Id, StringComparison.Ordinal);
             if (accepted) { _mirrorIdentityType = f.Type; _mirrorTraits = traits; }
             OnSdkStateChanged();
             var payload = new Dictionary<string, object>
@@ -237,20 +234,16 @@ private void OnAlias() => RunAndLog("alias()", () =>
         {
             var f = CaptureAliasForm();
             ImmutableAudience.Alias(f.FromId, ParseIdentityType(f.FromType), f.ToId, ParseIdentityType(f.ToType));
-            // SDK drops via Log.Warn when fromId/toId is empty or consent < Full.
-            // The IsAliasReady gate keeps empty endpoints unreachable from the
-            // UI; this post-call check is defense-in-depth.
-            var accepted = !string.IsNullOrEmpty(f.FromId) && !string.IsNullOrEmpty(f.ToId);
-            if (accepted)
-            {
-                _mirrorAliases.Add($"{f.FromType}:{f.FromId} → {f.ToType}:{f.ToId}");
-                OnSdkStateChanged();
-            }
+            // Empty/identical/malformed ids throw, caught by RunAndLog before this
+            // line runs. Consent below Full still drops silently inside the SDK,
+            // with no readable property here to detect it (unlike Identify's UserId).
+            _mirrorAliases.Add($"{f.FromType}:{f.FromId} → {f.ToType}:{f.ToId}");
+            OnSdkStateChanged();
             return Json.Serialize(new Dictionary<string, object>
             {
                 ["from"]     = new Dictionary<string, object> { ["id"] = f.FromId, ["identityType"] = f.FromType },
                 ["to"]       = new Dictionary<string, object> { ["id"] = f.ToId,   ["identityType"] = f.ToType },
-                ["accepted"] = accepted,
+                ["accepted"] = true,
             }, 2);
         });
 
@@ -292,6 +285,18 @@ private void RouteSdkLogToPane(string msg)
             {
                 UnityEngine.Debug.Log($"[Audience] {body}");
             }
+
+            if (body.StartsWith("flush ok", StringComparison.Ordinal))
+            {
+                AppendLog(body, null, LogLevel.Ok, LogSource.Sdk);
+                return;
+            }
+            if (body.StartsWith("flush failed", StringComparison.Ordinal))
+            {
+                AppendLog(body, null, LogLevel.Err, LogSource.Sdk);
+                return;
+            }
+
             AppendLog("sdk", body, level, LogSource.Sdk);
         }
 
diff --git a/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs b/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs
index aeb763f0..d949d28b 100644
--- a/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs
+++ b/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs
@@ -253,14 +253,16 @@ public IEnumerator Identify_AndFlush_FlushReportsOk()
         }
 
         [UnityTest]
-        public IEnumerator Identify_PassportWithInvalidIdFormat_WarnsAndDropsCall()
+        public IEnumerator Identify_PassportWithInvalidIdFormat_Throws()
         {
             // Identity type dropdown defaults to Passport; "12345" isn't Passport-shaped.
+            // ImmutableAudience.Identify throws on this; RunAndLog catches it and
+            // renders an identify()@Err row.
             yield return LoadAndInit(initialConsent: SampleAppUi.Consent.Full);
 
             _root!.Q<TextField>(SampleAppUi.IdentityFields.Id).value = "12345";
             _root.Q<Button>(SampleAppUi.Buttons.Identify).Click();
-            yield return SampleAppTestHelpers.WaitForLogEntry(_root, SampleAppUi.LogLabels.Sdk, LogLevels.Warn, 5f);
+            yield return SampleAppTestHelpers.WaitForLogEntry(_root, SampleAppUi.LogLabels.Identify, LogLevels.Err, 5f);
 
             Assert.IsNull(ImmutableAudience.UserId,
                 "an invalid Passport ID must be a full no-op, not just logged");
@@ -280,6 +282,23 @@ public IEnumerator Alias_AndFlush_FlushReportsOk()
             yield return FlushAndAssertNoErrors();
         }
 
+        [UnityTest]
+        public IEnumerator Alias_SameId_Throws()
+        {
+            // Type-independence (same id, different identityType is still
+            // rejected) is covered by the fast unit test
+            // Alias_IdenticalIdsDifferentTypes_StillThrows; this only needs to
+            // prove the UI path wires up to that same check. ImmutableAudience.Alias
+            // throws on this; RunAndLog catches it and renders an alias()@Err row.
+            yield return LoadAndInit(initialConsent: SampleAppUi.Consent.Full);
+
+            var sameId = "email|same-" + DateTime.UtcNow.Ticks;
+            _root!.Q<TextField>(SampleAppUi.IdentityFields.AliasFromId).value = sameId;
+            _root.Q<TextField>(SampleAppUi.IdentityFields.AliasToId).value = sameId;
+            _root.Q<Button>(SampleAppUi.Buttons.Alias).Click();
+            yield return SampleAppTestHelpers.WaitForLogEntry(_root, SampleAppUi.LogLabels.Alias, LogLevels.Err, 5f);
+        }
+
         [UnityTest]
         public IEnumerator SetConsent_None_KeepsQueueAndPersists()
         {
diff --git a/src/Packages/Audience/Runtime/Core/Constants.cs b/src/Packages/Audience/Runtime/Core/Constants.cs
index b13ac668..f2b22c07 100644
--- a/src/Packages/Audience/Runtime/Core/Constants.cs
+++ b/src/Packages/Audience/Runtime/Core/Constants.cs
@@ -14,6 +14,7 @@ internal static class Constants
         internal const int DefaultFlushSize = 20;
         internal const int MaxBatchSize = 100;
         internal const int StaleEventDays = 30;
+        internal const int MaxClockSkewFutureHours = 24; // Backend rejects eventTimestamp further ahead than this.
         internal const int MaxFieldLength = 256; // Backend schema limit.
         internal const int ControlPlaneRequestTimeoutSeconds = 30;
 
diff --git a/src/Packages/Audience/Runtime/ImmutableAudience.cs b/src/Packages/Audience/Runtime/ImmutableAudience.cs
index 750f3520..7826c21c 100644
--- a/src/Packages/Audience/Runtime/ImmutableAudience.cs
+++ b/src/Packages/Audience/Runtime/ImmutableAudience.cs
@@ -326,16 +326,15 @@ internal static void OnResume()
         /// Sends a typed event. Prefer over the string overload for
         /// compile-time required-field validation.
         /// </summary>
-        /// <param name="evt">The event to send.</param>
+        /// <param name="evt">The event to send. Must not be null, and <see cref="IEvent.EventName"/>
+        /// must not be empty (both throw).</param>
         public static void Track(IEvent evt)
         {
+            if (!_initialized) return;
+            if (evt == null) throw new ArgumentNullException(nameof(evt), AudienceLogs.TrackIEventNull);
+
             var state = _state;
-            if (!_initialized || !state.Level.CanTrack()) return;
-            if (evt == null)
-            {
-                Log.Warn(AudienceLogs.TrackIEventNull);
-                return;
-            }
+            if (!state.Level.CanTrack()) return;
 
             var config = _config;
             if (config == null) return;
@@ -355,10 +354,7 @@ public static void Track(IEvent evt)
             }
 
             if (string.IsNullOrEmpty(eventName))
-            {
-                Log.Warn(AudienceLogs.TrackIEventEmptyName(evt.GetType().Name));
-                return;
-            }
+                throw new ArgumentException(AudienceLogs.TrackIEventEmptyName(evt.GetType().Name), nameof(evt));
 
             // ToProperties returns a fresh dict per call, so no snapshot needed.
             EnqueueTrackedEvent(eventName, properties, _session?.SessionId, state, config);
@@ -369,17 +365,16 @@ public static void Track(IEvent evt)
         /// <c>resource</c>, and <c>milestone_reached</c>, prefer the typed
         /// overload.
         /// </summary>
-        /// <param name="eventName">The wire-format event name.</param>
+        /// <param name="eventName">The wire-format event name. Must not be empty (throws otherwise).</param>
         /// <param name="properties">Optional event properties.</param>
         public static void Track(string eventName, Dictionary<string, object>? properties = null)
         {
-            var state = _state;
-            if (!_initialized || !state.Level.CanTrack()) return;
+            if (!_initialized) return;
             if (string.IsNullOrEmpty(eventName))
-            {
-                Log.Warn(AudienceLogs.TrackStringEmptyName);
-                return;
-            }
+                throw new ArgumentException(AudienceLogs.TrackStringEmptyName, nameof(eventName));
+
+            var state = _state;
+            if (!state.Level.CanTrack()) return;
 
             var config = _config;
             if (config == null) return;
@@ -423,8 +418,7 @@ private static void TrackFromSession(string eventName, Dictionary<string, object
         /// <summary>
         /// Attaches a known user ID to subsequent events. When <paramref name="identityType"/> is
         /// <see cref="IdentityType.Passport"/>, <paramref name="userId"/> must look like a real
-        /// Passport ID (<c>connection|id</c> or a UUID) — otherwise the call is dropped and a
-        /// warning is logged.
+        /// Passport ID (<c>connection|id</c> or a UUID); otherwise this throws.
         /// </summary>
         /// <param name="userId">The player's identifier within the chosen provider.</param>
         /// <param name="identityType">The identity provider that issued <paramref name="userId"/>.</param>
@@ -433,21 +427,16 @@ public static void Identify(string userId, IdentityType identityType, Dictionary
         {
             if (!_initialized) return;
 
-            // Validate inputs before consent so null-arg callers get the right warning.
+            // Validate inputs before consent so a caller bug throws even when
+            // consent is below Full (a no-op should never mask a bad argument).
             if (string.IsNullOrEmpty(userId))
-            {
-                Log.Warn(AudienceLogs.IdentifyEmptyUserId);
-                return;
-            }
+                throw new ArgumentException(AudienceLogs.IdentifyEmptyUserId, nameof(userId));
 
             // Trim once: the validated id and the stored/sent id must match.
             userId = userId.Trim();
 
             if (identityType == IdentityType.Passport && !IsValidPassportId(userId))
-            {
-                Log.Warn(AudienceLogs.IdentifyPassportIdInvalidFormat(userId));
-                return;
-            }
+                throw new ArgumentException(AudienceLogs.IdentifyPassportIdInvalidFormat(userId), nameof(userId));
 
             AudienceConfig? config;
             ConsentLevel level;
@@ -482,10 +471,11 @@ private static bool IsValidPassportId(string id)
         }
 
         /// <summary>
-        /// Links two user IDs for the same player. When either side's identity
+        /// Links two user IDs for the same player. <paramref name="fromId"/> and
+        /// <paramref name="toId"/> must differ. When either side's identity
         /// type is <see cref="IdentityType.Passport"/>, that side's id must look
-        /// like a real Passport ID (<c>connection|id</c> or a UUID) — otherwise
-        /// the call is dropped and a warning is logged.
+        /// like a real Passport ID (<c>connection|id</c> or a UUID); otherwise
+        /// this throws.
         /// </summary>
         /// <param name="fromId">The previously-known identifier.</param>
         /// <param name="fromType">Identity provider for <paramref name="fromId"/>.</param>
@@ -496,25 +486,19 @@ public static void Alias(string fromId, IdentityType fromType, string toId, Iden
             if (!_initialized) return;
 
             if (string.IsNullOrEmpty(fromId) || string.IsNullOrEmpty(toId))
-            {
-                Log.Warn(AudienceLogs.AliasEmptyIds);
-                return;
-            }
+                throw new ArgumentException(AudienceLogs.AliasEmptyIds);
 
             // Trim once: the validated ids and the sent ids must match.
             fromId = fromId.Trim();
             toId = toId.Trim();
 
+            if (fromId == toId)
+                throw new ArgumentException(AudienceLogs.AliasIdenticalIds);
+
             if (fromType == IdentityType.Passport && !IsValidPassportId(fromId))
-            {
-                Log.Warn(AudienceLogs.AliasPassportIdInvalidFormat("from", fromId));
-                return;
-            }
+                throw new ArgumentException(AudienceLogs.AliasPassportIdInvalidFormat("from", fromId), nameof(fromId));
             if (toType == IdentityType.Passport && !IsValidPassportId(toId))
-            {
-                Log.Warn(AudienceLogs.AliasPassportIdInvalidFormat("to", toId));
-                return;
-            }
+                throw new ArgumentException(AudienceLogs.AliasPassportIdInvalidFormat("to", toId), nameof(toId));
 
             var state = _state;
             if (!state.Level.CanIdentify())
diff --git a/src/Packages/Audience/Runtime/Transport/DiskStore.cs b/src/Packages/Audience/Runtime/Transport/DiskStore.cs
index bee2c2c4..1fdb2b3f 100644
--- a/src/Packages/Audience/Runtime/Transport/DiskStore.cs
+++ b/src/Packages/Audience/Runtime/Transport/DiskStore.cs
@@ -39,8 +39,11 @@ internal void Write(string json)
             }
         }
 
-        // Returns up to maxSize file paths, oldest first. Stale files
-        // (older than Constants.StaleEventDays) are deleted and excluded.
+        // Returns up to maxSize file paths, oldest first. Files outside the
+        // backend's accepted eventTimestamp window (more than StaleEventDays
+        // in the past, or more than MaxClockSkewFutureHours in the future --
+        // e.g. from a device with a badly-skewed system clock) are deleted
+        // and excluded: the backend would reject them anyway.
         internal IReadOnlyList<string> ReadBatch(int maxSize)
         {
             if (maxSize <= 0)
@@ -48,7 +51,9 @@ internal IReadOnlyList<string> ReadBatch(int maxSize)
 
             maxSize = Math.Min(maxSize, Constants.MaxBatchSize);
 
-            var cutoff = DateTime.UtcNow.AddDays(-Constants.StaleEventDays);
+            var now = DateTime.UtcNow;
+            var pastCutoff = now.AddDays(-Constants.StaleEventDays);
+            var futureCutoff = now.AddHours(Constants.MaxClockSkewFutureHours);
 
             var result = new List<string>();
 
@@ -65,13 +70,13 @@ internal IReadOnlyList<string> ReadBatch(int maxSize)
                 if (result.Count >= maxSize)
                     break;
 
-                // Stale check: parse ticks from filename prefix
+                // Window check: parse ticks from filename prefix
                 var name = Path.GetFileNameWithoutExtension(path);
                 var underscoreIdx = name.IndexOf('_');
                 if (underscoreIdx > 0 && long.TryParse(name.Substring(0, underscoreIdx), out var ticks))
                 {
                     var fileTime = new DateTime(ticks, DateTimeKind.Utc);
-                    if (fileTime < cutoff)
+                    if (fileTime < pastCutoff || fileTime > futureCutoff)
                     {
                         TryDelete(path);
                         continue;
diff --git a/src/Packages/Audience/Runtime/Transport/HttpTransport.cs b/src/Packages/Audience/Runtime/Transport/HttpTransport.cs
index 4eefbbb5..fa62d067 100644
--- a/src/Packages/Audience/Runtime/Transport/HttpTransport.cs
+++ b/src/Packages/Audience/Runtime/Transport/HttpTransport.cs
@@ -113,6 +113,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
                         NotifyError(AudienceErrorCode.ValidationRejected,
                             $"Batch partially rejected: {rejected} of {batch.Count} events dropped");
                     }
+                    LogFlushOutcome(rejected == 0, batch.Count);
                 }
                 else if (statusCode == 429)
                 {
@@ -125,6 +126,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
                         SetBackoffUntil(_getUtcNow() + retryAfter.Value);
                     else
                         RecordFailure();
+                    LogFlushOutcome(false, batch.Count);
                 }
                 else if (statusCode >= 400 && statusCode < 500)
                 {
@@ -139,6 +141,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
                     ResetBackoff();
                     NotifyError(AudienceErrorCode.ValidationRejected,
                         FormatHttpError("Batch rejected", statusCode, rejectionBody));
+                    LogFlushOutcome(false, batch.Count);
                 }
                 else
                 {
@@ -148,6 +151,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
                     RecordFailure();
                     NotifyError(AudienceErrorCode.FlushFailed,
                         FormatHttpError("Server error, will retry", statusCode, serverBody));
+                    LogFlushOutcome(false, batch.Count);
                 }
             }
             catch (OperationCanceledException) when (ct.IsCancellationRequested)
@@ -166,6 +170,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
             {
                 RecordFailure();
                 NotifyError(AudienceErrorCode.NetworkError, ex.Message);
+                LogFlushOutcome(false, batch.Count);
             }
 
             return true;
@@ -342,5 +347,10 @@ private void NotifyError(AudienceErrorCode code, string message)
                 Log.Warn(AudienceLogs.OnErrorThrew(ex));
             }
         }
+
+        // Reports the real per-attempt result (2xx with zero rejections vs
+        // anything else), distinct from onError which only fires on failure.
+        private static void LogFlushOutcome(bool ok, int count) =>
+            Log.Debug(AudienceLogs.FlushOutcome(ok, count));
     }
-}
\ No newline at end of file
+}
diff --git a/src/Packages/Audience/Runtime/Utility/Log.cs b/src/Packages/Audience/Runtime/Utility/Log.cs
index 6a105711..976f8627 100644
--- a/src/Packages/Audience/Runtime/Utility/Log.cs
+++ b/src/Packages/Audience/Runtime/Utility/Log.cs
@@ -52,26 +52,35 @@ internal static class AudienceLogs
             "Call Shutdown() first if reconfiguring is intended.";
 
         // ---- Track ----
+        // Null event / empty event name are caller bugs: thrown as
+        // ArgumentException/ArgumentNullException, not logged (see ImmutableAudience.Track).
 
         internal const string TrackIEventNull =
-            "Track(IEvent) called with null event. Dropping.";
+            "Track(IEvent) called with null event.";
 
         internal const string TrackStringEmptyName =
-            "Track(string) called with null or empty event name. Dropping.";
+            "Track(string) called with null or empty event name.";
 
         internal static string TrackIEventThrew(string evtTypeName, Exception ex) =>
             $"Track(IEvent): {evtTypeName}.ToProperties()/EventName threw {ex.GetType().Name}: {ex.Message}. Dropping.";
 
         internal static string TrackIEventEmptyName(string evtTypeName) =>
-            $"Track(IEvent): {evtTypeName}.EventName returned null or empty. Dropping.";
+            $"Track(IEvent): {evtTypeName}.EventName returned null or empty.";
 
         // ---- Identify / Alias ----
+        // Empty/malformed ids are caller bugs: thrown as ArgumentException, not
+        // logged (see ImmutableAudience.Identify/Alias). IdentifyDiscarded/
+        // AliasDiscarded below are different: consent gating is a routine no-op,
+        // not a bug, so those stay as warnings.
 
         internal const string IdentifyEmptyUserId =
-            "Identify called with null or empty userId. Dropping.";
+            "Identify called with null or empty userId.";
 
         internal const string AliasEmptyIds =
-            "Alias called with null or empty fromId/toId. Dropping.";
+            "Alias called with null or empty fromId/toId.";
+
+        internal const string AliasIdenticalIds =
+            "Alias called with identical fromId and toId.";
 
         internal static string IdentifyDiscarded(ConsentLevel current) =>
             $"Identify discarded. Requires Full consent, current is {current}.";
@@ -79,7 +88,7 @@ internal static string IdentifyDiscarded(ConsentLevel current) =>
         internal static string IdentifyPassportIdInvalidFormat(string userId) =>
             $"Identify called with identityType Passport but userId \"{userId}\" doesn't look like a " +
             "Passport ID (expected a format like \"email|123\" or a UUID). Check you're passing the " +
-            "Passport user ID, not your own internal user ID. Call ignored.";
+            "Passport user ID, not your own internal user ID.";
 
         internal static string AliasDiscarded(ConsentLevel current) =>
             $"Alias discarded. Requires Full consent, current is {current}.";
@@ -87,7 +96,7 @@ internal static string AliasDiscarded(ConsentLevel current) =>
         internal static string AliasPassportIdInvalidFormat(string side, string id) =>
             $"Alias called with {side}Type Passport but {side}Id \"{id}\" doesn't look like a " +
             "Passport ID (expected a format like \"email|123\" or a UUID). Check you're passing the " +
-            "Passport user ID, not your own internal user ID. Call ignored.";
+            "Passport user ID, not your own internal user ID.";
 
         // ---- Consent / Shutdown ----
 
@@ -112,6 +121,9 @@ internal static string OnErrorThrew(Exception ex) =>
         internal static string SendBatchUnexpected(Exception ex) =>
             $"SendBatch unexpected exception: {ex.GetType().Name}: {ex.Message}";
 
+        internal static string FlushOutcome(bool ok, int count) =>
+            $"flush {(ok ? "ok" : "failed")} ({count} messages)";
+
         internal static string ParseRejectedCountThrew(Exception ex) =>
             $"ParseRejectedCount threw {ex.GetType().Name}: {ex.Message}";
 
diff --git a/src/Packages/Audience/Tests/Runtime/ImmutableAudienceTests.cs b/src/Packages/Audience/Tests/Runtime/ImmutableAudienceTests.cs
index f4e66f45..f32634db 100644
--- a/src/Packages/Audience/Tests/Runtime/ImmutableAudienceTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/ImmutableAudienceTests.cs
@@ -386,18 +386,22 @@ public void Init_CalledTwice_IgnoresSecondCall()
         }
 
         [Test]
-        public void Track_NullEvent_DoesNotThrow_AndLogsWarning()
+        public void Track_NullEvent_Throws()
         {
             ImmutableAudience.Init(MakeConfig());
 
-            var lines = new List<string>();
-            Log.Writer = lines.Add;
-            try
-            {
-                Assert.DoesNotThrow(() => ImmutableAudience.Track((IEvent)null));
-                Assert.That(lines, Has.Some.Contains(AudienceLogs.TrackIEventNull));
-            }
-            finally { Log.Writer = null; }
+            Assert.Throws<ArgumentNullException>(() => ImmutableAudience.Track((IEvent)null),
+                "a null event is a caller bug and must throw, not just log a warning that's easy to miss");
+        }
+
+        [Test]
+        public void Track_NullEvent_ThrowsEvenAtNoneConsent()
+        {
+            // A caller bug must throw regardless of consent; the None no-op
+            // must never mask a null event the way it masks a valid one.
+            ImmutableAudience.Init(MakeConfig(ConsentLevel.None));
+
+            Assert.Throws<ArgumentNullException>(() => ImmutableAudience.Track((IEvent)null));
         }
 
         [Test]
@@ -428,55 +432,31 @@ public void Track_IEventMissingRequiredField_DropsWithWarn()
         }
 
         [Test]
-        public void Track_NullOrEmptyEventName_DoesNotEnqueue()
+        public void Track_NullOrEmptyEventName_Throws()
         {
             ImmutableAudience.Init(MakeConfig());
 
-            Assert.DoesNotThrow(() => ImmutableAudience.Track((string)null));
-            Assert.DoesNotThrow(() => ImmutableAudience.Track(""));
-
-            ImmutableAudience.Shutdown();
-
-            // Assert the invariant directly: no enqueued message carries a
-            // null or empty eventName. Earlier versions counted files
-            // before/after the Track calls, which raced with the async
-            // disk drain: Init enqueues session_start + game_launch, and
-            // Shutdown adds session_end, so the file count after Shutdown
-            // is deterministic but the before-count is not. Counting is
-            // the wrong axis: what the test actually wants to pin is
-            // "no empty-name event ever hit the queue", regardless of
-            // what else was enqueued alongside it.
-            //
-            // Deserialize each message and inspect the eventName field
-            // directly. A raw substring scan would false-positive on an
-            // event whose property value happened to be the literal
-            // string "eventName":"" (unlikely but possible) and would
-            // silently break on any future JSON encoding change (whitespace,
-            // key ordering, escape style).
-            var queueDir = AudiencePaths.QueueDir(_testDir);
-            if (!Directory.Exists(queueDir)) return;
-            foreach (var file in Directory.GetFiles(queueDir, "*.json"))
-            {
-                var msg = JsonReader.DeserializeObject(File.ReadAllText(file));
-                if ((string)msg["type"] != "track") continue;
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Track((string)null),
+                "an empty event name is a caller bug and must throw, not just log a warning that's easy to miss");
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Track(""));
+        }
 
-                if (!msg.TryGetValue("eventName", out var eventNameObj))
-                    Assert.Fail($"track message {Path.GetFileName(file)} missing eventName field");
+        [Test]
+        public void Track_NullOrEmptyEventName_ThrowsEvenAtNoneConsent()
+        {
+            ImmutableAudience.Init(MakeConfig(ConsentLevel.None));
 
-                Assert.IsNotNull(eventNameObj,
-                    $"queue file {Path.GetFileName(file)} has a null eventName");
-                Assert.IsNotEmpty((string)eventNameObj,
-                    $"queue file {Path.GetFileName(file)} has an empty eventName");
-            }
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Track((string)null));
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Track(""));
         }
 
         [Test]
-        public void Identify_NullUserId_DoesNotEnqueue()
+        public void Identify_NullOrEmptyUserId_Throws()
         {
             ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
 
-            Assert.DoesNotThrow(() => ImmutableAudience.Identify(null, IdentityType.Passport));
-            Assert.DoesNotThrow(() => ImmutableAudience.Identify("", IdentityType.Passport));
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Identify(null, IdentityType.Passport));
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Identify("", IdentityType.Passport));
         }
 
         [Test]
@@ -506,12 +486,12 @@ public void Alias_InvalidIdentityTypeCast_Throws()
         }
 
         [Test]
-        public void Alias_NullIds_DoesNotEnqueue()
+        public void Alias_NullOrEmptyIds_Throws()
         {
             ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
 
-            Assert.DoesNotThrow(() => ImmutableAudience.Alias(null, IdentityType.Passport, "to", IdentityType.Steam));
-            Assert.DoesNotThrow(() => ImmutableAudience.Alias("from", IdentityType.Passport, "", IdentityType.Steam));
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Alias(null, IdentityType.Passport, "to", IdentityType.Steam));
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Alias("from", IdentityType.Passport, "", IdentityType.Steam));
         }
 
         [Test]
@@ -647,7 +627,7 @@ private class EmptyNameEvent : IEvent
         }
 
         [Test]
-        public void Track_TypedEvent_NullEventName_IsDropped()
+        public void Track_TypedEvent_NullEventName_Throws()
         {
             ImmutableAudience.Init(MakeConfig());
 
@@ -657,12 +637,13 @@ public void Track_TypedEvent_NullEventName_IsDropped()
             var queueDir = AudiencePaths.QueueDir(_testDir);
             foreach (var f in Directory.GetFiles(queueDir, "*.json")) File.Delete(f);
 
-            Assert.DoesNotThrow(() => ImmutableAudience.Track(new NullNameEvent()));
-            Assert.DoesNotThrow(() => ImmutableAudience.Track(new EmptyNameEvent()));
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Track(new NullNameEvent()),
+                "an IEvent with a null/empty EventName is a caller bug and must throw");
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Track(new EmptyNameEvent()));
 
             ImmutableAudience.FlushQueueToDiskForTesting();
             Assert.AreEqual(0, Directory.GetFiles(queueDir, "*.json").Length,
-                "IEvent with null/empty EventName must be dropped, not enqueued");
+                "IEvent with null/empty EventName must never reach the queue");
         }
 
         [Test]
@@ -738,33 +719,22 @@ public void Identify_AnonymousConsent_IsIgnored()
         }
 
         [Test]
-        public void Identify_PassportWithInvalidIdFormat_WarnsAndDropsCall()
+        public void Identify_PassportWithInvalidIdFormat_Throws()
         {
-            var lines = new List<string>();
-            Log.Writer = lines.Add;
-            try
-            {
-                ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
+            ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
 
-                ImmutableAudience.Identify("12345", IdentityType.Passport);
-                ImmutableAudience.Shutdown();
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Identify("12345", IdentityType.Passport),
+                "a malformed passport id is a caller bug and must throw, not just log a warning that's easy to miss");
+            Assert.IsNull(ImmutableAudience.UserId,
+                "the call must be a full no-op so later Track/Page calls don't inherit the bad id");
 
-                Assert.That(lines, Has.Some.Contains("doesn't look like a"),
-                    "a malformed passport id should surface a warning so a developer notices the mismatch");
-                Assert.IsNull(ImmutableAudience.UserId,
-                    "the call must be a full no-op so later Track/Page calls don't inherit the bad id");
+            ImmutableAudience.Shutdown();
 
-                var queueDir = AudiencePaths.QueueDir(_testDir);
-                var contents = Directory.GetFiles(queueDir, "*.json")
-                    .Select(File.ReadAllText).ToList();
-                Assert.IsFalse(contents.Any(c => c.Contains("\"identify\"")),
-                    "the event should be dropped, not just flagged; a warning alone isn't enough to " +
-                    "stop the bad id from reaching downstream analytics");
-            }
-            finally
-            {
-                Log.Writer = null;
-            }
+            var queueDir = AudiencePaths.QueueDir(_testDir);
+            var contents = Directory.GetFiles(queueDir, "*.json")
+                .Select(File.ReadAllText).ToList();
+            Assert.IsFalse(contents.Any(c => c.Contains("\"identify\"")),
+                "the event should never reach the queue");
         }
 
         [TestCase("email|abc123")]
@@ -790,23 +760,12 @@ public void Identify_PassportWithValidIdFormat_DoesNotWarn(string userId)
         }
 
         [Test]
-        public void Identify_PassportWithWhitespaceOnlyPadding_StillWarns()
+        public void Identify_PassportWithWhitespaceOnlyPadding_StillThrows()
         {
-            var lines = new List<string>();
-            Log.Writer = lines.Add;
-            try
-            {
-                ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
-
-                ImmutableAudience.Identify("  12345  ", IdentityType.Passport);
+            ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
 
-                Assert.That(lines, Has.Some.Contains("doesn't look like a"),
-                    "surrounding whitespace alone must not turn an invalid id into a valid one");
-            }
-            finally
-            {
-                Log.Writer = null;
-            }
+            Assert.Throws<ArgumentException>(() => ImmutableAudience.Identify("  12345  ", IdentityType.Passport),
+                "surrounding whitespace alone must not turn an invalid id into a valid one");
         }
 
         [Test]
@@ -880,57 +839,74 @@ public void Alias_FullConsent_WritesAliasEvent()
         }
 
         [Test]
-        public void Alias_PassportToWithInvalidIdFormat_WarnsAndDropsCall()
+        public void Alias_PassportToWithInvalidIdFormat_Throws()
         {
-            var lines = new List<string>();
-            Log.Writer = lines.Add;
-            try
-            {
-                ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
+            ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
 
-                ImmutableAudience.Alias("steam123", IdentityType.Steam, "12345", IdentityType.Passport);
-                ImmutableAudience.Shutdown();
+            Assert.Throws<ArgumentException>(
+                () => ImmutableAudience.Alias("steam123", IdentityType.Steam, "12345", IdentityType.Passport),
+                "a malformed passport id on the to side is a caller bug and must throw");
 
-                Assert.That(lines, Has.Some.Contains("doesn't look like a"),
-                    "a malformed passport id on the to side should surface a warning");
+            ImmutableAudience.Shutdown();
+            var queueDir = AudiencePaths.QueueDir(_testDir);
+            var contents = Directory.GetFiles(queueDir, "*.json")
+                .Select(File.ReadAllText).ToList();
+            Assert.IsFalse(contents.Any(c => c.Contains("\"alias\"")),
+                "the event should never reach the queue");
+        }
 
-                var queueDir = AudiencePaths.QueueDir(_testDir);
-                var contents = Directory.GetFiles(queueDir, "*.json")
-                    .Select(File.ReadAllText).ToList();
-                Assert.IsFalse(contents.Any(c => c.Contains("\"alias\"")),
-                    "the event should be dropped, not just flagged");
-            }
-            finally
-            {
-                Log.Writer = null;
-            }
+        [Test]
+        public void Alias_PassportFromWithInvalidIdFormat_Throws()
+        {
+            ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
+
+            Assert.Throws<ArgumentException>(
+                () => ImmutableAudience.Alias("12345", IdentityType.Passport, "steam123", IdentityType.Steam),
+                "a malformed passport id on the from side is a caller bug and must throw");
+
+            ImmutableAudience.Shutdown();
+            var queueDir = AudiencePaths.QueueDir(_testDir);
+            var contents = Directory.GetFiles(queueDir, "*.json")
+                .Select(File.ReadAllText).ToList();
+            Assert.IsFalse(contents.Any(c => c.Contains("\"alias\"")),
+                "the event should never reach the queue");
         }
 
         [Test]
-        public void Alias_PassportFromWithInvalidIdFormat_WarnsAndDropsCall()
+        public void Alias_IdenticalIds_Throws()
         {
-            var lines = new List<string>();
-            Log.Writer = lines.Add;
-            try
-            {
-                ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
+            ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
 
-                ImmutableAudience.Alias("12345", IdentityType.Passport, "steam123", IdentityType.Steam);
-                ImmutableAudience.Shutdown();
+            Assert.Throws<ArgumentException>(
+                () => ImmutableAudience.Alias("same_id", IdentityType.Steam, "same_id", IdentityType.Steam),
+                "identical ids are a caller bug and must throw");
 
-                Assert.That(lines, Has.Some.Contains("doesn't look like a"),
-                    "a malformed passport id on the from side should surface a warning");
+            ImmutableAudience.Shutdown();
+            var queueDir = AudiencePaths.QueueDir(_testDir);
+            var contents = Directory.GetFiles(queueDir, "*.json")
+                .Select(File.ReadAllText).ToList();
+            Assert.IsFalse(contents.Any(c => c.Contains("\"alias\"")),
+                "the event should never reach the queue");
+        }
 
-                var queueDir = AudiencePaths.QueueDir(_testDir);
-                var contents = Directory.GetFiles(queueDir, "*.json")
-                    .Select(File.ReadAllText).ToList();
-                Assert.IsFalse(contents.Any(c => c.Contains("\"alias\"")),
-                    "the event should be dropped, not just flagged");
-            }
-            finally
-            {
-                Log.Writer = null;
-            }
+        [Test]
+        public void Alias_IdenticalIdsDifferentTypes_StillThrows()
+        {
+            // Matches the backend: it rejects on id equality alone, ignoring
+            // identityType, so the client must reject this case too instead
+            // of sending something the backend will bounce.
+            ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
+
+            Assert.Throws<ArgumentException>(
+                () => ImmutableAudience.Alias("same_id", IdentityType.Steam, "same_id", IdentityType.Email),
+                "identical ids must throw even with different identityTypes");
+
+            ImmutableAudience.Shutdown();
+            var queueDir = AudiencePaths.QueueDir(_testDir);
+            var contents = Directory.GetFiles(queueDir, "*.json")
+                .Select(File.ReadAllText).ToList();
+            Assert.IsFalse(contents.Any(c => c.Contains("\"alias\"")),
+                "the event should never reach the queue");
         }
 
         [Test]
diff --git a/src/Packages/Audience/Tests/Runtime/Transport/DiskStoreTests.cs b/src/Packages/Audience/Tests/Runtime/Transport/DiskStoreTests.cs
index 268aa427..73b6ceec 100644
--- a/src/Packages/Audience/Tests/Runtime/Transport/DiskStoreTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Transport/DiskStoreTests.cs
@@ -106,6 +106,22 @@ public void ReadBatch_ExcludesAndDeletesStaleFiles()
             Assert.IsFalse(File.Exists(Path.Combine(queueDir, staleName)), "stale file should be deleted");
         }
 
+        [Test]
+        public void ReadBatch_ExcludesAndDeletesFutureSkewedFiles()
+        {
+            _store.Write("{\"fresh\":true}");
+
+            var skewedTime = DateTime.UtcNow.AddHours(Constants.MaxClockSkewFutureHours + 1);
+            var skewedName = $"{skewedTime.Ticks}_{Guid.NewGuid():N}.json";
+            var queueDir = AudiencePaths.QueueDir(_testDir);
+            File.WriteAllText(Path.Combine(queueDir, skewedName), "{\"skewed\":true}");
+
+            var batch = _store.ReadBatch(10);
+
+            Assert.AreEqual(1, batch.Count, "future-skewed file should be excluded from batch");
+            Assert.IsFalse(File.Exists(Path.Combine(queueDir, skewedName)), "future-skewed file should be deleted");
+        }
+
         [Test]
         public void Delete_RemovesSpecifiedFiles()
         {
diff --git a/src/Packages/Audience/Tests/Runtime/Transport/HttpTransportTests.cs b/src/Packages/Audience/Tests/Runtime/Transport/HttpTransportTests.cs
index 4f336597..6e662e3b 100644
--- a/src/Packages/Audience/Tests/Runtime/Transport/HttpTransportTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Transport/HttpTransportTests.cs
@@ -1,6 +1,7 @@
 #nullable enable
 
 using System;
+using System.Collections.Generic;
 using System.IO;
 #if IMMUTABLE_AUDIENCE_GZIP
 using System.IO.Compression;
@@ -338,6 +339,55 @@ public async Task SendBatchAsync_200_ZeroRejected_DoesNotFireOnError()
             Assert.IsNull(reportedError, "zero rejected must not fire onError");
         }
 
+        [Test]
+        public async Task SendBatchAsync_200_ZeroRejected_LogsFlushOk()
+        {
+            // onError only fires on failure; this is the only per-attempt signal a send succeeded.
+            _store.Write("{\"type\":\"track\",\"eventName\":\"a\"}");
+
+            var handler = new MockHandler(HttpStatusCode.OK, "{\"accepted\":1,\"rejected\":0}");
+            using var transport = new HttpTransport(_store, "pk_imapik-test-key1", handler: handler);
+
+            var lines = new List<string>();
+            Log.Enabled = true;
+            Log.Writer = lines.Add;
+            try
+            {
+                await transport.SendBatchAsync();
+            }
+            finally
+            {
+                Log.Writer = null;
+                Log.Enabled = false;
+            }
+
+            Assert.That(lines, Has.Some.Contains("flush ok (1 messages)"));
+        }
+
+        [Test]
+        public async Task SendBatchAsync_500_LogsFlushFailed()
+        {
+            _store.Write("{\"type\":\"track\",\"eventName\":\"a\"}");
+
+            var handler = new MockHandler(HttpStatusCode.InternalServerError, "");
+            using var transport = new HttpTransport(_store, "pk_imapik-test-key1", handler: handler);
+
+            var lines = new List<string>();
+            Log.Enabled = true;
+            Log.Writer = lines.Add;
+            try
+            {
+                await transport.SendBatchAsync();
+            }
+            finally
+            {
+                Log.Writer = null;
+                Log.Enabled = false;
+            }
+
+            Assert.That(lines, Has.Some.Contains("flush failed (1 messages)"));
+        }
+
         [Test]
         public async Task SendBatchAsync_200_MalformedBody_TreatsAsZeroRejected()
         {