Yeah, deleting a couple of the tilemap_bitmaps and reloading doesn't do anything to the editor; it doesn't even remove those tilemaps, they just bug out and don't load when you start the game. Therefore I conclude that adding some, no matter what you do with the scripts isn't going to change anything either. Short of maybe hex editing the game editor .exe in some uber ways, this is not going to change. I even went through the data files with a hex editor trying to see if there was anywhere where this was editable, there's not.
So doucheface is a doubledouche with meatsauce for 1. bullshitting, 2, getting people's hopes up, and 3. acting like a total cockmastering sack of post-consumer vaginal grease when challenged on it.