Yeah, TWHL Tower had a 128 unit buffer, because anything more would break the illusion of a tower. Not accessible by the player, but useful for balconies and such. I think only Dr.Orange and I made use of this?
With TWHL Pockets, you can essentially put anything you want in your map, but the playable area must fit within a 1024 unit cube (with allowances for walking along the surface of the uppermost brush)