I've made some progress today on writing a predefined Classicvania room transition. While trying to work out a minor issue with my custom transition for the Name Entry and Password screens, I fiddled a bit with Torigara's Room Transition Tutorial and ran a couple tests. I succeeded in making an instance not perform its Draw Event until after the room transition has completed. It's an ugly method as far as I am concerned, but for the general populace, it should suffice. So having now, for the time being, solved this problem, I can work out a custom room transition so rooms connected by doors can be designed separately as they should rather than all in one large room.