Ah, apologies for missing the entire bit about the documentation. I wents hands on, immediately there. I think everything else appears to be even made in such a way that it all explains itself then.
Kinda wish I was able to freely define the dimensions of doors for purely creative reasons, but only because I'm spoiled from mid-90s Doom wad editing, where I would create doors the shape of an X in the center of a plus intersection of corridors and such. ^^
You rock, I'm back playing with the editor.