What does this do?
EditorUtility.SmartResetGameObjectToPrefabState
I have a bug where the prefab being created is not complete and I need more documentation to find out why?
It Resets the properties of the component or game object to the parent prefab state. All overrides will be cleared. However the transform.position and rotation of a root game object in a prefab instance will never be cleared.
In short, it’s probably not what you are looking for 
Is there anyway to reset the rotation value?