diff --git a/src/libraries/Microsoft.PowerFx.Transport.Attributes/TransportMethodAttribute.cs b/src/libraries/Microsoft.PowerFx.Transport.Attributes/TransportMethodAttribute.cs
index 236bb2f81b..ba9d1cec8e 100644
--- a/src/libraries/Microsoft.PowerFx.Transport.Attributes/TransportMethodAttribute.cs
+++ b/src/libraries/Microsoft.PowerFx.Transport.Attributes/TransportMethodAttribute.cs
@@ -11,9 +11,8 @@ namespace Microsoft.AppMagic.Transport
     [AttributeUsage(AttributeTargets.Method)]
     public class TransportMethodAttribute : Attribute
     {
-        public TransportMethodAttribute(bool supportSynchronousClient = false, TransportBatchingMode batchingMode = TransportBatchingMode.Default, bool isParallel = false)
+        public TransportMethodAttribute(TransportBatchingMode batchingMode = TransportBatchingMode.Default, bool isParallel = false)
         {
-            SupportSynchronousClient = supportSynchronousClient;
             BatchingMode = batchingMode;
             IsParallel = isParallel;
         }
@@ -23,11 +22,6 @@ public TransportMethodAttribute(bool supportSynchronousClient = false, Transport
         /// </summary>
         public bool Deferred { get; }
 
-        /// <summary>
-        /// For back-compat, support blocking callers.
-        /// </summary>
-        public bool SupportSynchronousClient { get; }
-
         /// <summary>
         /// Defines batching.
         /// </summary>
diff --git a/src/libraries/Microsoft.PowerFx.Transport.Attributes/TransportPropertyAttribute.cs b/src/libraries/Microsoft.PowerFx.Transport.Attributes/TransportPropertyAttribute.cs
index 2b776c0b26..f57a5d4088 100644
--- a/src/libraries/Microsoft.PowerFx.Transport.Attributes/TransportPropertyAttribute.cs
+++ b/src/libraries/Microsoft.PowerFx.Transport.Attributes/TransportPropertyAttribute.cs
@@ -11,20 +11,11 @@ namespace Microsoft.AppMagic.Transport
     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
     public class TransportPropertyAttribute : Attribute
     {
-        public TransportPropertyAttribute(bool generateSynchronousSetterTemplateInProxyClass = false, bool useDiffSync = false)
+        public TransportPropertyAttribute(bool useDiffSync = false)
         {
-            GenerateSynchronousSetterTemplateInProxyClass = generateSynchronousSetterTemplateInProxyClass;
             UseDiffSync = useDiffSync;
         }
 
-        /// <summary>
-        /// When defined, generates a synchronous setter method that redirects to "set{PropertyName}". This
-        /// allows the programmer to manually define how set calls should be marshalled. The user is still
-        /// responsible for defining the appropriate setter method in either the base class or original
-        /// C# class.
-        /// </summary>
-        public bool GenerateSynchronousSetterTemplateInProxyClass { get; }
-
         /// <summary>
         /// If the marked property is a <c>ITrackedCollection</c>, and it gets updated,
         /// state synchronization will not send the entire collection to the client, only