Hey folks. The old link in the previous thread about this is dead, and it also has some spam in it, so I thought it'd be easier to just create a new thread with the updated link to the Speed Demos Archive post about the game:

https://forum.speeddemosarchive.com/post/adventure_island_ii_nes__discussion_thread.html

Lots of good info in there about how to manipulate routing, and now folks shouldn't have to Google around for it anymore.