diff --git a/conftest.py b/conftest.py
index 99736e738e1..f6251fceba5 100644
--- a/conftest.py
+++ b/conftest.py
@@ -191,15 +191,14 @@ def cuda_param(val):
     return pytest.param(val, marks=[pytest.mark.llvm, pytest.mark.cuda])
 
 @pytest.helpers.register
-def get_func_execution(func, func_mode, *, writeback:bool=True):
+def get_func_execution(func, func_mode):
     if func_mode == 'LLVM':
         ex = pnlvm.execution.FuncExecution(func)
 
         # Calling writeback here will replace parameter values
         # with numpy instances that share memory with the binary
         # structure used by the compiled function
-        if writeback:
-            ex.writeback_state_to_pnl()
+        ex.writeback_state_to_pnl()
 
         return ex.execute
 
@@ -209,8 +208,7 @@ def get_func_execution(func, func_mode, *, writeback:bool=True):
         # Calling writeback here will replace parameter values
         # with numpy instances that share memory with the binary
         # structure used by the compiled function
-        if writeback:
-            ex.writeback_state_to_pnl()
+        ex.writeback_state_to_pnl()
 
         return ex.cuda_execute
 
@@ -222,9 +220,25 @@ def get_func_execution(func, func_mode, *, writeback:bool=True):
 @pytest.helpers.register
 def get_mech_execution(mech, mech_mode):
     if mech_mode == 'LLVM':
-        return pnlvm.execution.MechExecution(mech).execute
+        ex = pnlvm.execution.MechExecution(mech)
+
+        # Calling writeback here will replace parameter values
+        # with numpy instances that share memory with the binary
+        # structure used by the compiled function
+        ex.writeback_state_to_pnl()
+
+        return ex.execute
+
     elif mech_mode == 'PTX':
-        return pnlvm.execution.MechExecution(mech).cuda_execute
+        ex = pnlvm.execution.MechExecution(mech)
+
+        # Calling writeback here will replace parameter values
+        # with numpy instances that share memory with the binary
+        # structure used by the compiled function
+        ex.writeback_state_to_pnl()
+
+        return ex.cuda_execute
+
     elif mech_mode == 'Python':
         def mech_wrapper(x):
             mech.execute(x)
diff --git a/psyneulink/core/llvm/execution.py b/psyneulink/core/llvm/execution.py
index 55838dd845d..9af8f8e86d5 100644
--- a/psyneulink/core/llvm/execution.py
+++ b/psyneulink/core/llvm/execution.py
@@ -158,6 +158,21 @@ def _copy_params_to_pnl(self, context, component, params, ids:str, condition:Cal
                                              ids=ids,
                                              condition=condition)
             else:
+                # TODO: Reconstruct Python RandomState
+                if attribute == "random_state":
+                    continue
+
+                # TODO: Reconstruct Python memory storage
+                if attribute == "ring_memory":
+                    continue
+
+                # "old_val" is a helper storage in compiled RecurrentTransferMechanism
+                # to workaround the fact that compiled projections do no pull values
+                # from their source output ports
+                # recurrent projection of RTM is not a PNL parameter.
+                if attribute in {"old_val", "recurrent_projection"}:
+                    continue
+
                 # Handle PNL parameters
                 pnl_param = getattr(component.parameters, attribute)
                 pnl_value = pnl_param.get(context=context)
@@ -183,10 +198,6 @@ def _copy_params_to_pnl(self, context, component, params, ids:str, condition:Cal
                 # Writeback parameter value if the condition matches
                 elif condition(pnl_param):
 
-                    # TODO: Reconstruct Python RandomState
-                    if attribute == "random_state":
-                        continue
-
                     # Replace empty structures with None
                     if ctypes.sizeof(compiled_attribute_param) == 0:
                         value = None
@@ -202,7 +213,7 @@ def _copy_params_to_pnl(self, context, component, params, ids:str, condition:Cal
                         if hasattr(old_value, 'shape'):
                             value = value.reshape(old_value.shape)
 
-                    pnl_param.set(value, context=context)
+                    pnl_param.set(value, context=context, override=True)
 
 
 class CUDAExecution(Execution):
diff --git a/tests/functions/test_memory.py b/tests/functions/test_memory.py
index b1b7bf64f13..7c1dbbbc19c 100644
--- a/tests/functions/test_memory.py
+++ b/tests/functions/test_memory.py
@@ -144,9 +144,7 @@ def test_basic(func, variable, params, expected, benchmark, func_mode):
     if variable is philox_var:
         f.parameters.random_state.set(_SeededPhilox([module_seed]))
 
-    # Do not allow writeback. "ring_memory" used by DictionaryMemory is a
-    # custom structure, not a PNL parameter
-    EX = pytest.helpers.get_func_execution(f, func_mode, writeback=False)
+    EX = pytest.helpers.get_func_execution(f, func_mode)
 
     EX(variable)