After a bit of thought and some time looking at WPF canvas and related items I realized that the same VR environment I planned to use for the random dungeon generator (toy program to play with Unity some more) would make a good environment for putting together an interactive room layout editor.
I was going to try to put together a room drawing tool in WPF. I would prefer to build something like that with interactive drawing as the user moves the mouse. Looking at WPF drawing primitives it seems as if that would get ugly quickly as I really want something closer to a rendering environment. Each frame should be redrawn with updates from any user input reflected.
The 2D APIs seem much more oriented towards static drawings. Update on clicks rather than the 3D style display lists where the image on the screen gets updated continuously. Given the hardware available on even low powered modern computers there is no good reason not to provide this sort of constant, interactive feedback (the equivalent of WSYWG for office tools 30 years ago.
Unity VR provides all of the tools to make this sort of thing happen and should actually provide a very pleasant UI experience along the way. I think I’ll try putting together a map drawing tool as an interesting exercise soon. It may or may not be the final approach but it seems worth trying.