Say, that is a very creative solution! OK, so here's where I am at now. I put an event square trigger with the $81 subcommand with a transition time of 0 right on the spot that you enter from the world map so that it triggers right when the map loads, but there is a still a very slight millisecond of the song playing full volume before it triggers - it's very close to working but it is just too noticeable to leave.
So I thought that maybe you changed what song the map loads in LE to either current or silent, so that it does not play the song full volume at all, but current makes it play the Overworld music longer while the map loads and it fades a bit, and even lags and I don't have a 'silence' song anymore, so I hope that isn't the answer; but I would guess that the brief instance of the song playing at full volume is in fact due to the map being set to play the song...? Might you have happened to change that, or could I be missing something else?
Also, there seems to be no noticeable beneficial change if I remove the entrance event for the room and I think it would still be needed for coming through the other doors, right? Unless you also added event triggers at the other 3 doors, but I doubt you did that as event trigger squares ain't easy to come by nowadays =D
Thank you!