MC_PRE_CHANGE_ROOM appears to have no effect/is broken
Returning a table that's just the target room index and dimension in of itself doesn't appear to do anything. Doing {TargetRoomIndex = X, Dimension = Y} (obviously replacing X and Y with proper values), it just repeatedly sends you back to the current room you tried to exit from. This is broken in both release and the nightly.
I used this in one of my mods recently, and found that I had to set "level.LeaveDoor = DoorSlot.NO_DOOR_SLOT" to make it work correctly. I'm using the most recent version for rep. I haven't tested the rep+ nightly.
It's likely related to this bug: https://github.com/epfly6/RepentanceAPIIssueTracker/issues/244
Edit: My return value just looked like this:
return { 149, Dimension.MINESHAFT }
Should be fixed in b9fff5117bddfbed03e5124bde25ca913a32aa34