Clarified comment for duplicating materials

cura/Machines/Models/MaterialManagementModel.py

@@ -141,7 +141,8 @@ class MaterialManagementModel(QObject):
                 new_container.getMetaData().update(new_metadata)
             new_containers.append(new_container)
 
-        # Optimization. Serving the same purpose as the postponeSignals() in removeMaterial()
+        # postpone the signals emitted when duplicating materials. This is easier on the event loop; changes the
+        # behavior to be like a transaction. Prevents concurrency issues.
         with postponeSignals(container_registry.containerAdded, compress=CompressTechnique.CompressPerParameterValue):
             for container_to_add in new_containers:
                 container_to_add.setDirty(True)