When I was making 3d floor planner I needed to cut holes in walls to make doorways. I couldn’t use 3d model of hole cause there isn’t 3d model of empty space and the hole itself required to be with adjustable size so I hacked backend model of door to add some data with empty 3d model and stored all of the positions instead to load that and cut those holes on walls manually.
So it become door without door model. Doorway.
It worked like a charm.