diff --git a/cdisc_rules_engine/utilities/dataset_preprocessor.py b/cdisc_rules_engine/utilities/dataset_preprocessor.py
index f58a787f3..c1c8ed8f8 100644
--- a/cdisc_rules_engine/utilities/dataset_preprocessor.py
+++ b/cdisc_rules_engine/utilities/dataset_preprocessor.py
@@ -347,7 +347,7 @@ def _merge_standard_then_filter_idvar(
                     if col not in merged_record:
                         merged_record[col] = None
             results.append(merged_record)
-        return child_records.__class__.from_records(results)
+        return pd.DataFrame.from_records(results)
 
     def _filter_parents_by_standard_keys(
         self,
@@ -479,7 +479,7 @@ def _merge_idvar_only(
                     if col not in merged_record:
                         merged_record[col] = None
             results.append(merged_record)
-        return child_records.__class__.from_records(results)
+        return pd.DataFrame.from_records(results)
 
     def _update_dataset_with_merged_records(
         self,
diff --git a/cdisc_rules_engine/utilities/rule_processor.py b/cdisc_rules_engine/utilities/rule_processor.py
index 3f8a5a961..1f93f0885 100644
--- a/cdisc_rules_engine/utilities/rule_processor.py
+++ b/cdisc_rules_engine/utilities/rule_processor.py
@@ -373,6 +373,10 @@ def perform_rule_operations(
                 target = BaseOperation._replace_variable_wildcard(
                     target, wildcard_replacement
                 )
+            if domain and domain.startswith(("SUPP", "SQ")) and domain.endswith("--"):
+                rdomain = getattr(dataset_metadata, "rdomain", None)
+                if rdomain:
+                    domain = domain.replace("--", rdomain)
 
             # get necessary operation
             operation_params = OperationParams(