I just noticed an odd bug with regions. If you do a blockable (or non) walk off a region the 'when player walks off region' interaction never triggers. I know it can't happen during the walk (unless you put in some code to have it break the walkcycle when they stepped off of it, which would work), but it's something that should certainly be queued to happen after the walk finishes. A Nonblock walk with Wait() seems to work sometimes, though it's a bit dodgy. It's something I think would be good to fix since you might want to force the player off a pressure plate and have something happen.
While in a blocking situation, various script calls queue up, such as repeatedly_execute, Player Walks On Region, etc. Because no event has a higher priority than any others, your Walks Off Region event is probably being displaced by a few rep_execs coming along.
It's an interesting point, I'm not sure what they best way forward is.
What I would do in this case is moving the region code to Repeatedly_execute_always.