Just a quick idea:
I’d love to be able to have buildings that show a little that’s going on inside them. For that, an archway of 6 or 8 width would be perfect. This way, you could create open shop fronts that will still register as walls (so they will disappear when you use the see-through-view). If you do it manually, the walls will remain, and also they don’t look as intricate as the door frames or windows do.