Super Secret Area - Dead Ahead!
I think I get what you are saying. You're talking about out-of-bounds travel. There's a detailed page by Kejardon on it here.
I can't see it making a difference, however as when you touch a door tile, and trigger the transition, the game has set properties attached to the door, detailing where it spits you out. This means that no matter where you were in relation to your Room B, when you touch the door transition tiles, it'll spit you out of the same door in Room M. The only way to get to Botwoon's door would be from the only door linked to it (the room on the other side of it), which you can't get to for obvious reasons.
Hope that makes sense.
I can't see it making a difference, however as when you touch a door tile, and trigger the transition, the game has set properties attached to the door, detailing where it spits you out. This means that no matter where you were in relation to your Room B, when you touch the door transition tiles, it'll spit you out of the same door in Room M. The only way to get to Botwoon's door would be from the only door linked to it (the room on the other side of it), which you can't get to for obvious reasons.
Hope that makes sense.