diff --git a/frameworks/effinitive/app/Models.cs b/frameworks/effinitive/app/Models.cs
index 1b7eeb599..b5fbb0ce0 100644
--- a/frameworks/effinitive/app/Models.cs
+++ b/frameworks/effinitive/app/Models.cs
@@ -34,8 +34,10 @@ public sealed class ProcessedItem
     public double Price { get; set; }
     public int Quantity { get; set; }
     public bool Active { get; set; }
-    public List<string> Tags { get; set; } = [];
-    public RatingInfo Rating { get; set; } = new();
+    // Suppress default-init: these are always set in the endpoint loop so
+    // the default [] / new() would be immediately discarded (wasted alloc).
+    public List<string> Tags { get; set; } = null!;
+    public RatingInfo Rating { get; set; } = null!;
     public double Total { get; set; }
 }
 
diff --git a/frameworks/effinitive/app/Tests/Json.cs b/frameworks/effinitive/app/Tests/Json.cs
index 3fad33232..50e779ce7 100644
--- a/frameworks/effinitive/app/Tests/Json.cs
+++ b/frameworks/effinitive/app/Tests/Json.cs
@@ -4,7 +4,9 @@
 
 namespace effinitive.Tests;
 
-public class JsonEndpoint : NoRequestEndpointBase<ResponseDto<ProcessedItem>>
+// Returns byte[] so SerializeResponse short-circuits into the pre-serialized path,
+// bypassing reflection-based JsonSerializerOptions entirely.
+public class JsonEndpoint : NoRequestEndpointBase<byte[]>
 {
     protected override string Method => "GET";
     protected override string Route => "/json/{count}";
@@ -24,7 +26,7 @@ private static DatasetItem[] LoadItems()
         return [.. items];
     }
 
-    public override ValueTask<ResponseDto<ProcessedItem>> HandleAsync(CancellationToken ct)
+    public override ValueTask<byte[]> HandleAsync(CancellationToken ct)
     {
         var query = HttpContext?.Query ?? QueryCollection.Empty;
         int count = int.TryParse(HttpContext?.RouteValues?["count"]?.ToString(), out var c) ? c : AllItems.Length;
@@ -44,6 +46,8 @@ public override ValueTask<ResponseDto<ProcessedItem>> HandleAsync(CancellationTo
             };
         }
 
-        return ValueTask.FromResult(new ResponseDto<ProcessedItem>(processed, take));
+        var dto = new ResponseDto<ProcessedItem>(processed, take);
+        return ValueTask.FromResult(
+            JsonSerializer.SerializeToUtf8Bytes(dto, AppJsonContext.Default.ResponseDtoProcessedItem));
     }
 }
diff --git a/frameworks/effinitive/app/effinitive-arena.csproj b/frameworks/effinitive/app/effinitive-arena.csproj
index 91d77a275..ff8f8cd12 100644
--- a/frameworks/effinitive/app/effinitive-arena.csproj
+++ b/frameworks/effinitive/app/effinitive-arena.csproj
@@ -11,7 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="EffinitiveFramework.Core" Version="2.0.0" />
+    <PackageReference Include="EffinitiveFramework.Core" Version="2.1.1" />
     <PackageReference Include="Microsoft.Data.Sqlite" Version="10.0.5" />
     <PackageReference Include="Npgsql" Version="10.0.2" />
   </ItemGroup>
diff --git a/frameworks/effinitive/meta.json b/frameworks/effinitive/meta.json
index 9b398267a..5f28e8c3a 100644
--- a/frameworks/effinitive/meta.json
+++ b/frameworks/effinitive/meta.json
@@ -12,6 +12,7 @@
     "pipelined",
     "limited-conn",
     "json",
+    "json-comp",
     "upload",
     "api-4",
     "api-16",