diff --git a/AyCode.Core.Serializers.Console/BenchmarkTestDataProvider.cs b/AyCode.Core.Serializers.Console/BenchmarkTestDataProvider.cs
new file mode 100644
index 0000000..ab3a521
--- /dev/null
+++ b/AyCode.Core.Serializers.Console/BenchmarkTestDataProvider.cs
@@ -0,0 +1,234 @@
+using AyCode.Core.Serializers.Binaries;
+using AyCode.Core.Tests.TestModels;
+
+namespace AyCode.Core.Serializers.Console;
+
+internal static class BenchmarkTestDataProvider
+{
+    internal static List<TestDataSet> CreateTestDataSets()
+    {
+        return new List<TestDataSet>
+        {
+            CreateSmallTestData(),
+            CreateMediumTestData(),
+            CreateLargeTestData(),
+            CreateRepeatedStringsTestData(),
+            CreateDeepNestedTestData()
+        };
+    }
+
+    internal static TestOrder CreateProfilerOrder()
+    {
+        TestDataFactory.ResetIdCounter();
+        var sharedTag = TestDataFactory.CreateTag("SharedTag");
+        var sharedUser = TestDataFactory.CreateUser("shareduser");
+        return TestDataFactory.CreateOrder(
+            itemCount: 3,
+            palletsPerItem: 3,
+            measurementsPerPallet: 3,
+            pointsPerMeasurement: 4,
+            sharedTag: sharedTag,
+            sharedUser: sharedUser);
+    }
+
+    private static TestDataSet CreateSmallTestData()
+    {
+        TestDataFactory.ResetIdCounter();
+
+        var sharedTag = TestDataFactory.CreateTag("SharedTag");
+        var sharedUser = TestDataFactory.CreateUser("shareduser");
+
+        var order = TestDataFactory.CreateOrder(
+            itemCount: 2,
+            palletsPerItem: 2,
+            measurementsPerPallet: 2,
+            pointsPerMeasurement: 2,
+            sharedTag: sharedTag,
+            sharedUser: sharedUser);
+
+        ClearDeepLevelRefs(order);
+
+        return new TestDataSet("Small (2x2x2x2)", order, iidRefPercent: 10);
+    }
+
+    private static TestDataSet CreateMediumTestData()
+    {
+        TestDataFactory.ResetIdCounter();
+
+        var sharedTag = TestDataFactory.CreateTag("SharedTag");
+        var sharedUser = TestDataFactory.CreateUser("shareduser");
+        var sharedMeta = TestDataFactory.CreateMetadata("shared", withChild: true);
+
+        var sharedPreferences = new UserPreferences
+        {
+            Theme = "dark",
+            Language = "en-US",
+            NotificationsEnabled = true,
+            EmailDigestFrequency = "weekly"
+        };
+        sharedUser.Preferences = sharedPreferences;
+
+        var order = TestDataFactory.CreateOrder(
+            itemCount: 3,
+            palletsPerItem: 3,
+            measurementsPerPallet: 3,
+            pointsPerMeasurement: 4,
+            sharedTag: sharedTag,
+            sharedUser: sharedUser,
+            sharedMetadata: sharedMeta,
+            sharedPreferences: sharedPreferences);
+
+        ClearDeepLevelRefs(order);
+
+        return new TestDataSet("Medium (3x3x3x4)", order, iidRefPercent: 10);
+    }
+
+    private static TestDataSet CreateLargeTestData()
+    {
+        TestDataFactory.ResetIdCounter();
+
+        var sharedTag = TestDataFactory.CreateTag("SharedTag");
+        var sharedUser = TestDataFactory.CreateUser("shareduser");
+
+        var sharedPreferences = new UserPreferences
+        {
+            Theme = "light",
+            Language = "de-DE",
+            NotificationsEnabled = false,
+            EmailDigestFrequency = "daily"
+        };
+        sharedUser.Preferences = sharedPreferences;
+
+        var order = TestDataFactory.CreateOrder(
+            itemCount: 5,
+            palletsPerItem: 5,
+            measurementsPerPallet: 5,
+            pointsPerMeasurement: 10,
+            sharedTag: sharedTag,
+            sharedUser: sharedUser,
+            sharedPreferences: sharedPreferences);
+
+        ClearDeepLevelRefs(order);
+
+        return new TestDataSet("Large (5x5x5x10)", order, iidRefPercent: 10);
+    }
+
+    private static TestDataSet CreateRepeatedStringsTestData()
+    {
+        TestDataFactory.ResetIdCounter();
+
+        var sharedTag = TestDataFactory.CreateTag("RepeatedTag");
+        var sharedUser = TestDataFactory.CreateUser("repeateduser");
+
+        var sharedPreferences = new UserPreferences
+        {
+            Theme = "dark",
+            Language = "en-US",
+            NotificationsEnabled = true,
+            EmailDigestFrequency = "weekly"
+        };
+        sharedUser.Preferences = sharedPreferences;
+
+        var order = TestDataFactory.CreateOrder(
+            itemCount: 10,
+            palletsPerItem: 2,
+            measurementsPerPallet: 2,
+            pointsPerMeasurement: 2,
+            sharedTag: sharedTag,
+            sharedUser: sharedUser,
+            sharedPreferences: sharedPreferences);
+
+        foreach (var item in order.Items)
+        {
+            item.Status = TestStatus.Processing;
+            item.ProductName = "CommonProductName_RepeatedForTesting";
+        }
+
+        ClearDeepLevelRefs(order);
+
+        return new TestDataSet("Repeated Strings (10 items)", order, iidRefPercent: 10);
+    }
+
+    private static TestDataSet CreateDeepNestedTestData()
+    {
+        TestDataFactory.ResetIdCounter();
+
+        var sharedTag = TestDataFactory.CreateTag("DeepTag");
+        var sharedUser = TestDataFactory.CreateUser("deepuser");
+        var sharedCategory = TestDataFactory.CreateCategory("DeepCategory");
+
+        var sharedPreferences = new UserPreferences
+        {
+            Theme = "light",
+            Language = "fr-FR",
+            NotificationsEnabled = false,
+            EmailDigestFrequency = "monthly"
+        };
+        sharedUser.Preferences = sharedPreferences;
+
+        var order = TestDataFactory.CreateOrder(
+            itemCount: 2,
+            palletsPerItem: 4,
+            measurementsPerPallet: 4,
+            pointsPerMeasurement: 8,
+            sharedTag: sharedTag,
+            sharedUser: sharedUser,
+            sharedPreferences: sharedPreferences,
+            sharedCategory: sharedCategory);
+
+        ClearDeepLevelRefs(order);
+
+        return new TestDataSet("Deep Nested (2x4x4x8)", order, iidRefPercent: 10);
+    }
+
+    private static void ClearDeepLevelRefs(TestOrder order)
+    {
+        foreach (var item in order.Items)
+        {
+            foreach (var pallet in item.Pallets)
+            {
+                pallet.Tag = null;
+                pallet.Inspector = null;
+                pallet.Category = null;
+
+                foreach (var measurement in pallet.Measurements)
+                {
+                    measurement.Tag = null;
+                    measurement.Operator = null;
+
+                    foreach (var point in measurement.Points)
+                    {
+                        point.Tag = null;
+                        point.Verifier = null;
+                    }
+                }
+            }
+        }
+    }
+}
+
+internal sealed class TestDataSet
+{
+    public string Name { get; }
+    public TestOrder Order { get; }
+
+    /// <summary>
+    /// Percentage of IId shared references in the data (0-100).
+    /// Higher values mean more deduplication benefit for Default mode.
+    /// </summary>
+    public int IIdRefPercent { get; }
+
+    public TestDataSet(string name, TestOrder order, int iidRefPercent = 0)
+    {
+        Name = name;
+        Order = order;
+        IIdRefPercent = iidRefPercent;
+    }
+
+    /// <summary>
+    /// Gets display name including IId ref percentage if set.
+    /// </summary>
+    public string DisplayName => IIdRefPercent > 0
+        ? $"{Name} [{IIdRefPercent}% IId refs]"
+        : Name;
+}
diff --git a/AyCode.Core.Serializers.Console/Program.cs b/AyCode.Core.Serializers.Console/Program.cs
index 6a5ee75..4da051a 100644
--- a/AyCode.Core.Serializers.Console/Program.cs
+++ b/AyCode.Core.Serializers.Console/Program.cs
@@ -68,7 +68,7 @@ public static class Program
         }
 
         // Profiler mode: warmup only, then exit (for memory profiler analysis)
-        //if (mode == "profiler")
+        if (mode == "profiler")
         {
             RunProfilerMode();
             return;
@@ -82,7 +82,7 @@ public static class Program
         System.Console.WriteLine();
 
         var allResults = new List<BenchmarkResult>();
-        var testDataSets = CreateTestDataSets();
+        var testDataSets = BenchmarkTestDataProvider.CreateTestDataSets();
 
         foreach (var testData in testDataSets)
         {
@@ -115,17 +115,7 @@ public static class Program
         System.Console.WriteLine($"Build: {BuildConfiguration} | .NET: {Environment.Version}");
         System.Console.WriteLine();
 
-        // Create medium test data
-        TestDataFactory.ResetIdCounter();
-        var sharedTag = TestDataFactory.CreateTag("SharedTag");
-        var sharedUser = TestDataFactory.CreateUser("shareduser");
-        var order = TestDataFactory.CreateOrder(
-            itemCount: 3,
-            palletsPerItem: 3,
-            measurementsPerPallet: 3,
-            pointsPerMeasurement: 4,
-            sharedTag: sharedTag,
-            sharedUser: sharedUser);
+        var order = BenchmarkTestDataProvider.CreateProfilerOrder();
 
         var options = AcBinarySerializerOptions.WithoutReferenceHandling;
         options.UseStringInterning = StringInterningMode.None;
@@ -167,217 +157,6 @@ public static class Program
         System.Console.WriteLine("✓ Profiler mode complete. Exiting now.");
     }
 
-    #region Test Data Creation
-
-    private static List<TestDataSet> CreateTestDataSets()
-    {
-        return new List<TestDataSet>
-        {
-            CreateSmallTestData(),
-            CreateMediumTestData(),
-            CreateLargeTestData(),
-            CreateRepeatedStringsTestData(),
-            CreateDeepNestedTestData()
-        };
-    }
-
-    private static TestDataSet CreateSmallTestData()
-    {
-        TestDataFactory.ResetIdCounter();
-
-        // Create shared references - IId types (only at Order/Item level)
-        var sharedTag = TestDataFactory.CreateTag("SharedTag");
-        var sharedUser = TestDataFactory.CreateUser("shareduser");
-
-        var order = TestDataFactory.CreateOrder(
-            itemCount: 2,
-            palletsPerItem: 2,
-            measurementsPerPallet: 2,
-            pointsPerMeasurement: 2,
-            sharedTag: sharedTag,
-            sharedUser: sharedUser);
-
-        // Clear deeper level refs for realistic ~10% ratio
-        ClearDeepLevelRefs(order);
-
-        return new TestDataSet("Small (2x2x2x2)", order, iidRefPercent: 10);
-    }
-
-    private static TestDataSet CreateMediumTestData()
-    {
-        TestDataFactory.ResetIdCounter();
-
-        // IId shared references
-        var sharedTag = TestDataFactory.CreateTag("SharedTag");
-        var sharedUser = TestDataFactory.CreateUser("shareduser");
-        var sharedMeta = TestDataFactory.CreateMetadata("shared", withChild: true);
-
-        // Non-IId shared reference - create separate preferences for 2 users
-        var sharedPreferences = new UserPreferences
-        {
-            Theme = "dark",
-            Language = "en-US",
-            NotificationsEnabled = true,
-            EmailDigestFrequency = "weekly"
-        };
-        sharedUser.Preferences = sharedPreferences;
-
-        var order = TestDataFactory.CreateOrder(
-            itemCount: 3,
-            palletsPerItem: 3,
-            measurementsPerPallet: 3,
-            pointsPerMeasurement: 4,
-            sharedTag: sharedTag,
-            sharedUser: sharedUser,
-            sharedMetadata: sharedMeta,
-            sharedPreferences: sharedPreferences);
-
-        // Clear deeper level refs for realistic ~10% ratio
-        ClearDeepLevelRefs(order);
-
-        return new TestDataSet("Medium (3x3x3x4)", order, iidRefPercent: 10);
-    }
-
-    private static TestDataSet CreateLargeTestData()
-    {
-        TestDataFactory.ResetIdCounter();
-
-        // IId shared references
-        var sharedTag = TestDataFactory.CreateTag("SharedTag");
-        var sharedUser = TestDataFactory.CreateUser("shareduser");
-
-        // Non-IId shared reference
-        var sharedPreferences = new UserPreferences
-        {
-            Theme = "light",
-            Language = "de-DE",
-            NotificationsEnabled = false,
-            EmailDigestFrequency = "daily"
-        };
-        sharedUser.Preferences = sharedPreferences;
-
-        var order = TestDataFactory.CreateOrder(
-            itemCount: 5,
-            palletsPerItem: 5,
-            measurementsPerPallet: 5,
-            pointsPerMeasurement: 10,
-            sharedTag: sharedTag,
-            sharedUser: sharedUser,
-            sharedPreferences: sharedPreferences);
-
-        // Clear deeper level refs for realistic ~10% ratio
-        ClearDeepLevelRefs(order);
-
-        return new TestDataSet("Large (5x5x5x10)", order, iidRefPercent: 10);
-    }
-
-    private static TestDataSet CreateRepeatedStringsTestData()
-    {
-        TestDataFactory.ResetIdCounter();
-
-        // IId shared references
-        var sharedTag = TestDataFactory.CreateTag("RepeatedTag");
-        var sharedUser = TestDataFactory.CreateUser("repeateduser");
-
-        // Non-IId shared reference
-        var sharedPreferences = new UserPreferences
-        {
-            Theme = "dark",
-            Language = "en-US",
-            NotificationsEnabled = true,
-            EmailDigestFrequency = "weekly"
-        };
-        sharedUser.Preferences = sharedPreferences;
-
-        // Create order with many items to test string interning on repeated property names
-        var order = TestDataFactory.CreateOrder(
-            itemCount: 10,
-            palletsPerItem: 2,
-            measurementsPerPallet: 2,
-            pointsPerMeasurement: 2,
-            sharedTag: sharedTag,
-            sharedUser: sharedUser,
-            sharedPreferences: sharedPreferences);
-
-        // Set same status and ProductName on all items to test enum and string handling
-        foreach (var item in order.Items)
-        {
-            item.Status = TestStatus.Processing;
-            item.ProductName = "CommonProductName_RepeatedForTesting";
-        }
-
-        // Clear deeper level refs for realistic ~10% ratio
-        ClearDeepLevelRefs(order);
-
-        return new TestDataSet("Repeated Strings (10 items)", order, iidRefPercent: 10);
-    }
-
-    /// <summary>
-    /// Clears IId shared references from Pallet, Measurement, and Point levels.
-    /// This creates a realistic ~10% IId ref ratio (only Order and Item levels have refs).
-    /// </summary>
-    private static void ClearDeepLevelRefs(TestOrder order)
-    {
-        foreach (var item in order.Items)
-        {
-            foreach (var pallet in item.Pallets)
-            {
-                pallet.Tag = null;
-                pallet.Inspector = null;
-                pallet.Category = null;
-
-                foreach (var measurement in pallet.Measurements)
-                {
-                    measurement.Tag = null;
-                    measurement.Operator = null;
-
-                    foreach (var point in measurement.Points)
-                    {
-                        point.Tag = null;
-                        point.Verifier = null;
-                    }
-                }
-            }
-        }
-    }
-
-    private static TestDataSet CreateDeepNestedTestData()
-    {
-        TestDataFactory.ResetIdCounter();
-
-        // IId shared references - only at Order and Item levels for ~10% ratio
-        var sharedTag = TestDataFactory.CreateTag("DeepTag");
-        var sharedUser = TestDataFactory.CreateUser("deepuser");
-        var sharedCategory = TestDataFactory.CreateCategory("DeepCategory");
-
-        // Non-IId shared reference
-        var sharedPreferences = new UserPreferences
-        {
-            Theme = "light",
-            Language = "fr-FR",
-            NotificationsEnabled = false,
-            EmailDigestFrequency = "monthly"
-        };
-        sharedUser.Preferences = sharedPreferences;
-
-        var order = TestDataFactory.CreateOrder(
-            itemCount: 2,
-            palletsPerItem: 4,
-            measurementsPerPallet: 4,
-            pointsPerMeasurement: 8,
-            sharedTag: sharedTag,
-            sharedUser: sharedUser,
-            sharedPreferences: sharedPreferences,
-            sharedCategory: sharedCategory);
-
-        // Clear deeper level refs for realistic ~10% ratio
-        ClearDeepLevelRefs(order);
-
-        return new TestDataSet("Deep Nested (2x4x4x8)", order, iidRefPercent: 10);
-    }
-
-    #endregion
-
     #region Benchmark Execution
 
     private static List<BenchmarkResult> RunBenchmarksForTestData(TestDataSet testData, string mode)
@@ -556,8 +335,11 @@ public static class Program
         {
             _order = order;
             Name = name;
-            _options = ContractlessStandardResolver.Options.WithCompression(MessagePackCompression.None);
+
+            //_options = ContractlessStandardResolver.Options.WithCompression(MessagePackCompression.None);
             //_options = ContractlessStandardResolver.Options.WithCompression(MessagePackCompression.Lz4Block);
+            _options = MessagePackSerializerOptions.Standard.WithCompression(MessagePackCompression.None);
+            
             _serialized = MessagePackSerializer.Serialize(order, _options);
         }
 
@@ -660,34 +442,6 @@ public static class Program
 
     #region Results
 
-    private sealed class TestDataSet
-    {
-        public string Name { get; }
-        public TestOrder Order { get; }
-
-        /// <summary>
-        /// Percentage of IId shared references in the data (0-100).
-        /// Higher values mean more deduplication benefit for Default mode.
-        /// </summary>
-        public int IIdRefPercent { get; }
-
-        public TestDataSet(string name, TestOrder order, int iidRefPercent = 0)
-        {
-            Name = name;
-            Order = order;
-            IIdRefPercent = iidRefPercent;
-        }
-
-        /// <summary>
-        /// Gets display name including IId ref percentage if set.
-        /// </summary>
-        public string DisplayName => IIdRefPercent > 0
-            ? $"{Name} [{IIdRefPercent}% IId refs]"
-            : Name;
-    }
-
-
-
     private sealed class BenchmarkResult
     {
         public string TestDataName { get; set; } = "";
diff --git a/AyCode.Core.Tests/TestModels/SharedTestModels.cs b/AyCode.Core.Tests/TestModels/SharedTestModels.cs
index c22959e..3f04e1c 100644
--- a/AyCode.Core.Tests/TestModels/SharedTestModels.cs
+++ b/AyCode.Core.Tests/TestModels/SharedTestModels.cs
@@ -53,14 +53,22 @@ public enum TestUserRole
 /// Implements IId&lt;int&gt; for semantic $id/$ref serialization.
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class SharedTag : IId<int>
 {
+    [Key(0)]
     public int Id { get; set; }
+    [Key(1)]
     public string Name { get; set; } = "";
+    [Key(2)]
     public string Color { get; set; } = "#000000";
+    [Key(3)]
     public int Priority { get; set; }
+    [Key(4)]
     public bool IsActive { get; set; } = true;
+    [Key(5)]
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    [Key(6)]
     public string? Description { get; set; }
 }
 
@@ -68,15 +76,24 @@ public class SharedTag : IId<int>
 /// Shared category - for hierarchical cross-reference testing.
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class SharedCategory : IId<int>
 {
+    [Key(0)]
     public int Id { get; set; }
+    [Key(1)]
     public string Name { get; set; } = "";
+    [Key(2)]
     public string? Description { get; set; }
+    [Key(3)]
     public int SortOrder { get; set; }
+    [Key(4)]
     public bool IsDefault { get; set; }
+    [Key(5)]
     public int? ParentCategoryId { get; set; }
+    [Key(6)]
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    [Key(7)]
     public DateTime? UpdatedAt { get; set; }
 }
 
@@ -84,17 +101,28 @@ public class SharedCategory : IId<int>
 /// Shared user reference - appears in many places to test $ref deduplication.
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class SharedUser : IId<int>
 {
+    [Key(0)]
     public int Id { get; set; }
+    [Key(1)]
     public string Username { get; set; } = "";
+    [Key(2)]
     public string Email { get; set; } = "";
+    [Key(3)]
     public string FirstName { get; set; } = "";
+    [Key(4)]
     public string LastName { get; set; } = "";
+    [Key(5)]
     public bool IsActive { get; set; } = true;
+    [Key(6)]
     public TestUserRole Role { get; set; } = TestUserRole.User;
+    [Key(7)]
     public DateTime? LastLoginAt { get; set; }
+    [Key(8)]
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    [Key(9)]
     public UserPreferences? Preferences { get; set; }
 }
 
@@ -102,11 +130,16 @@ public class SharedUser : IId<int>
 /// User preferences - non-IId nested object
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class UserPreferences
 {
+    [Key(0)]
     public string Theme { get; set; } = "light";
+    [Key(1)]
     public string Language { get; set; } = "en-US";
+    [Key(2)]
     public bool NotificationsEnabled { get; set; } = true;
+    [Key(3)]
     public string? EmailDigestFrequency { get; set; }
 }
 
@@ -119,15 +152,20 @@ public class UserPreferences
 /// Does NOT implement IId, so uses standard Newtonsoft reference tracking.
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class MetadataInfo
 {
+    [Key(0)]
     public string Key { get; set; } = "";
+    [Key(1)]
     public string Value { get; set; } = "";
+    [Key(2)]
     public DateTime Timestamp { get; set; } = DateTime.UtcNow;
     
     /// <summary>
     /// Nested metadata for deep Newtonsoft reference testing
     /// </summary>
+    [Key(3)]
     public MetadataInfo? ChildMetadata { get; set; }
 }
 
@@ -139,34 +177,51 @@ public class MetadataInfo
 /// Level 1: Main order - root of the hierarchy
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class TestOrder : IId<int>
 {
+    [Key(0)]
     public int Id { get; set; }
+    [Key(1)]
     public string OrderNumber { get; set; } = "";
+    [Key(2)]
     public TestStatus Status { get; set; } = TestStatus.Pending;
+    [Key(3)]
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    [Key(4)]
     public DateTime? PaidDateUtc { get; set; }
+    [Key(5)]
     public decimal TotalAmount { get; set; }
 
     // Level 2 collection
+    [Key(6)]
     public List<TestOrderItem> Items { get; set; } = [];
 
     // Shared reference properties (for $id/$ref testing)
+    [Key(7)]
     public SharedTag? PrimaryTag { get; set; }
+    [Key(8)]
     public SharedTag? SecondaryTag { get; set; }
+    [Key(9)]
     public SharedUser? Owner { get; set; }
+    [Key(10)]
     public SharedCategory? Category { get; set; }
     
     // Collection of shared references
+    [Key(11)]
     public List<SharedTag> Tags { get; set; } = [];
 
     // Non-IId metadata (for Newtonsoft $ref testing)
+    [Key(12)]
     public MetadataInfo? OrderMetadata { get; set; }
+    [Key(13)]
     public MetadataInfo? AuditMetadata { get; set; }
+    [Key(14)]
     public List<MetadataInfo> MetadataList { get; set; } = [];
 
     // NoMerge collection for testing replace behavior
     [JsonNoMergeCollection]
+    [Key(15)]
     public List<TestOrderItem> NoMergeItems { get; set; } = [];
 
     // Parent reference - ignored by all serializers to prevent circular references
@@ -180,20 +235,30 @@ public class TestOrder : IId<int>
 /// Level 2: Order item with pallets
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class TestOrderItem : IId<int>
 {
+    [Key(0)]
     public int Id { get; set; }
+    [Key(1)]
     public string ProductName { get; set; } = "";
+    [Key(2)]
     public int Quantity { get; set; }
+    [Key(3)]
     public decimal UnitPrice { get; set; }
+    [Key(4)]
     public TestStatus Status { get; set; } = TestStatus.Pending;
 
     // Level 3 collection
+    [Key(5)]
     public List<TestPallet> Pallets { get; set; } = [];
 
     // Shared references
+    [Key(6)]
     public SharedTag? Tag { get; set; }
+    [Key(7)]
     public SharedUser? Assignee { get; set; }
+    [Key(8)]
     public MetadataInfo? ItemMetadata { get; set; }
 
     // Parent reference - ignored by all serializers to prevent circular references
@@ -207,23 +272,34 @@ public class TestOrderItem : IId<int>
 /// Level 3: Pallet containing measurements
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class TestPallet : IId<int>
 {
+    [Key(0)]
     public int Id { get; set; }
+    [Key(1)]
     public string PalletCode { get; set; } = "";
+    [Key(2)]
     public int TrayCount { get; set; }
+    [Key(3)]
     public TestStatus Status { get; set; } = TestStatus.Pending;
+    [Key(4)]
     public double Weight { get; set; }
 
     // Level 4 collection
+    [Key(5)]
     public List<TestMeasurement> Measurements { get; set; } = [];
 
     // Shared IId references for better reference testing
+    [Key(6)]
     public SharedTag? Tag { get; set; }
+    [Key(7)]
     public SharedUser? Inspector { get; set; }
+    [Key(8)]
     public SharedCategory? Category { get; set; }
     
     // Non-IId shared references
+    [Key(9)]
     public MetadataInfo? PalletMetadata { get; set; }
 
     // Parent reference - ignored by all serializers to prevent circular references
@@ -237,18 +313,26 @@ public class TestPallet : IId<int>
 /// Level 4: Measurement with multiple points
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class TestMeasurement : IId<int>
 {
+    [Key(0)]
     public int Id { get; set; }
+    [Key(1)]
     public string Name { get; set; } = "";
+    [Key(2)]
     public double TotalWeight { get; set; }
+    [Key(3)]
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
 
     // Level 5 collection
+    [Key(4)]
     public List<TestMeasurementPoint> Points { get; set; } = [];
 
     // Shared IId references for better reference testing
+    [Key(5)]
     public SharedTag? Tag { get; set; }
+    [Key(6)]
     public SharedUser? Operator { get; set; }
 
     // Parent reference - ignored by all serializers to prevent circular references
@@ -262,15 +346,22 @@ public class TestMeasurement : IId<int>
 /// Level 5: Deepest level - measurement point
 /// </summary>
 [AcBinarySerializable]
+[MessagePackObject]
 public class TestMeasurementPoint : IId<int>
 {
+    [Key(0)]
     public int Id { get; set; }
+    [Key(1)]
     public string Label { get; set; } = "";
+    [Key(2)]
     public double Value { get; set; }
+    [Key(3)]
     public DateTime MeasuredAt { get; set; } = DateTime.UtcNow;
 
     // Shared IId reference for better reference testing (many points share same tag/user)
+    [Key(4)]
     public SharedTag? Tag { get; set; }
+    [Key(5)]
     public SharedUser? Verifier { get; set; }
 
     // Parent reference - ignored by all serializers to prevent circular references
diff --git a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs
index 3b5ad3a..a2c3636 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs
@@ -415,14 +415,15 @@ public static partial class AcBinaryDeserializer
 
             if (stringCache.TryGetValue(hash, out var cached))
             {
-                // Hash includes all bytes for short strings, so collision is extremely unlikely
-                // For longer strings, we still verify length as a sanity check
-                if (cached.Length == length)
+                // CRITICAL: Verify actual content matches to prevent hash collision data corruption.
+                // cached.Length is char count, length is UTF-8 byte count — equal only for ASCII.
+                // For ASCII strings (common case): byte-by-byte comparison against UTF-8 buffer.
+                if (cached.Length == length && VerifyAsciiUtf8Match(cached, slice))
                 {
                     _position += length;
                     return cached;
                 }
-                // Hash collision with different length - fall through to read new value
+                // Hash collision or non-ASCII length mismatch - fall through to decode
             }
 
             var value = Utf8NoBom.GetString(slice);
@@ -431,6 +432,22 @@ public static partial class AcBinaryDeserializer
             return value;
         }
 
+        /// <summary>
+        /// Verifies that a cached ASCII string matches the UTF-8 bytes exactly.
+        /// For ASCII, each char's low byte equals the UTF-8 byte.
+        /// Caller guarantees cached.Length == utf8Bytes.Length (ASCII invariant).
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static bool VerifyAsciiUtf8Match(string cached, ReadOnlySpan<byte> utf8Bytes)
+        {
+            for (var i = 0; i < cached.Length; i++)
+            {
+                if ((byte)cached[i] != utf8Bytes[i])
+                    return false;
+            }
+            return true;
+        }
+
         /// <summary>
         /// Compute hash that includes ALL bytes for short strings to avoid collisions.
         /// 
diff --git a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.Populate.cs b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.Populate.cs
index 85db77a..8d47eed 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.Populate.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.Populate.cs
@@ -155,8 +155,7 @@ public static partial class AcBinaryDeserializer
             var positionBeforeRead = context.Position;
             try
             {
-                // Use typed setters for primitives to avoid boxing
-                // Skip method call for Object/String/Collection types - they can't use typed setters
+                // Use typed setters for primitives and strings to avoid ReadValue dispatch
                 if (propInfo.AccessorType != PropertyAccessorType.Object &&
                     TryReadAndSetTypedValue(ref context, target, propInfo, peekCode))
                     continue;
diff --git a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs
index f92f6f3..adb8a03 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs
@@ -915,6 +915,40 @@ public static partial class AcBinaryDeserializer
                     return true;
                 }
                 break;
+
+            case PropertyAccessorType.String:
+                if (BinaryTypeCode.IsFixStr(peekCode))
+                {
+                    context.ReadByte();
+                    var length = BinaryTypeCode.DecodeFixStrLength(peekCode);
+                    propInfo.SetValue(target, length == 0 ? string.Empty : context.ReadStringUtf8(length));
+                    return true;
+                }
+                if (peekCode == BinaryTypeCode.String)
+                {
+                    context.ReadByte();
+                    propInfo.SetValue(target, ReadPlainString(ref context));
+                    return true;
+                }
+                if (peekCode == BinaryTypeCode.StringEmpty)
+                {
+                    context.ReadByte();
+                    propInfo.SetValue(target, string.Empty);
+                    return true;
+                }
+                if (peekCode == BinaryTypeCode.StringInterned)
+                {
+                    context.ReadByte();
+                    propInfo.SetValue(target, context.GetInternedString((int)context.ReadVarUInt()));
+                    return true;
+                }
+                if (peekCode == BinaryTypeCode.StringInternFirst)
+                {
+                    context.ReadByte();
+                    propInfo.SetValue(target, ReadAndRegisterInternedString(ref context));
+                    return true;
+                }
+                break;
         }
 
         return false;
diff --git a/AyCode.Core/Serializers/Binaries/AcBinarySerializer.cs b/AyCode.Core/Serializers/Binaries/AcBinarySerializer.cs
index 5f8775f..20f8394 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinarySerializer.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinarySerializer.cs
@@ -412,6 +412,24 @@ public static partial class AcBinarySerializer
         if (TryWritePrimitive(value, type, context))
             return;
 
+        WriteValueNonPrimitive(value, type, context, depth);
+    }
+
+    /// <summary>
+    /// Writes a non-primitive value (collection, dictionary, byte[], or complex object).
+    /// Skips null check and TryWritePrimitive — caller guarantees value is non-null and not a primitive type.
+    /// Called from WritePropertyOrSkip default case (PropertyAccessorType.Object) and WriteValue fallback.
+    /// </summary>
+    private static void WriteValueNonPrimitive(object value, Type type, BinarySerializationContext context, int depth)
+    {
+        // Nullable<T> where T is a value type: boxed value may be a primitive.
+        // Only Nullable<T> can be a value type in the Object accessor path.
+        if (type.IsValueType)
+        {
+            if (TryWritePrimitive(value, value.GetType(), context))
+                return;
+        }
+
         if (depth > context.MaxDepth)
         {
             context.WriteByte(BinaryTypeCode.Null);
@@ -1243,7 +1261,8 @@ public static partial class AcBinarySerializer
                 }
             default:
                 {
-                    // Object type - use regular getter
+                    // Object type (collection, complex object, byte[], dictionary)
+                    // TryWritePrimitive is always false for these — skip it via WriteValueNonPrimitive
                     var value = prop.GetValue(obj);
 
                     // SKIP marker only for null (reference types)
@@ -1257,7 +1276,7 @@ public static partial class AcBinarySerializer
 #if DEBUG
                         context.CurrentPropertyPath = $"{prop.DeclaringType.Name}.{prop.Name}";
 #endif
-                        WriteValue(value, prop.PropertyType, context, depth);
+                        WriteValueNonPrimitive(value, prop.PropertyType, context, depth);
                     }
                     return;
                 }
diff --git a/AyCode.Core/Serializers/Binaries/AcBinarySerializerOptions.cs b/AyCode.Core/Serializers/Binaries/AcBinarySerializerOptions.cs
index f58ef46..927b822 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinarySerializerOptions.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinarySerializerOptions.cs
@@ -82,7 +82,7 @@ public sealed class AcBinarySerializerOptions : AcSerializerOptions
     /// allowing the deserializer to match properties by name between different types.
     /// Default: false (no overhead)
     /// </summary>
-    public bool UseMetadata { get; init; } = false;
+    public bool UseMetadata { get; init; } = true;
 
     /// <summary>
     /// When true, checks for duplicate property name hashes during serialization (UseMetadata mode).