This is one of those things that I really SHOULD know, given how long I have had VX Ace, yet I find I just can't remember what the answer is...
Is there any difference between sections B, C, D, and E? i.e. A1 is animated autotiles, so you want to only put those types of tiles in there, A4 is walls, which again have their own specialized behavior so you can't just put anything you want in A4... etc.
But for B-E, is there any actual impact to a given type of tile being in, say, C vs E? I believe the answer is no, but as I said, I just can't remember.