diff --git a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs
index 88de2d6..25fe89b 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs
@@ -169,7 +169,7 @@ public static partial class AcBinaryDeserializer
         
         /// <summary>
         /// Reads string intern footer: [dupCount][pos0][idx0][pos1][idx1]...
-        /// Fixed int32 format for ultra-fast MemoryMarshal.Cast bulk read.
+        /// VarUInt format read into flat int[] for fast hot path access.
         /// </summary>
         private void ReadFooterStringIndices(int footerPosition)
         {
@@ -179,7 +179,7 @@ public static partial class AcBinaryDeserializer
             // Seek to footer
             _position = footerPosition;
 
-            // Read dup count (still VarUInt for backward compat header)
+            // Read dup count
             var dupCount = (int)ReadVarUInt();
             if (dupCount == 0)
             {
@@ -189,14 +189,14 @@ public static partial class AcBinaryDeserializer
             }
             else
             {
-                // Bulk read: dupCount * 2 int32s (position, cacheIndex pairs)
+                // Read VarUInt pairs into flat int[]
                 var intCount = dupCount * 2;
-                var byteCount = intCount * sizeof(int);
-                EnsureAvailable(byteCount);
-
                 _dupData = new int[intCount];
-                MemoryMarshal.Cast<byte, int>(_buffer.Slice(_position, byteCount)).CopyTo(_dupData);
-                _position += byteCount;
+                for (var i = 0; i < dupCount; i++)
+                {
+                    _dupData[i * 2] = (int)ReadVarUInt();      // position
+                    _dupData[i * 2 + 1] = (int)ReadVarUInt();  // cacheIndex
+                }
 
                 _internStringCache = new string[dupCount];
                 // Cache first dup position for ultra-fast hot path
diff --git a/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs b/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
index ef5fd5a..c85c47f 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
@@ -237,7 +237,7 @@ public static partial class AcBinarySerializer
 
         /// <summary>
         /// Writes the footer with (position, cacheIndex) pairs sorted by position.
-        /// Fixed int32 format for ultra-fast MemoryMarshal.Cast bulk read in deserializer.
+        /// VarUInt format for compact size, deserializer reads into flat int[].
         /// </summary>
         public void WriteInternedStringFooter()
         {
@@ -261,17 +261,12 @@ public static partial class AcBinarySerializer
             // Sort by StreamPosition (ascending) for deserializer sequential check
             entries.Sort((a, b) => a.Position.CompareTo(b.Position));
 
-            // Write pairs as fixed int32s: [pos0][idx0][pos1][idx1]...
-            // This allows MemoryMarshal.Cast bulk read in deserializer
-            var byteCount = _nextCacheIndex * 2 * sizeof(int);
-            EnsureCapacity(byteCount);
-            var dest = MemoryMarshal.Cast<byte, int>(_buffer.AsSpan(_position, byteCount));
+            // Write pairs as VarUInt for compact size
             for (var i = 0; i < _nextCacheIndex; i++)
             {
-                dest[i * 2] = entries[i].Position;
-                dest[i * 2 + 1] = entries[i].CacheIndex;
+                WriteVarUInt((uint)entries[i].Position);
+                WriteVarUInt((uint)entries[i].CacheIndex);
             }
-            _position += byteCount;
         }
 
         #endregion