I have no issue with fixing up my models in 3ds Max and reimporting. That’s a fine pipeline. What I want to do is procedural building modeling. Keep the modular workflow in the editor but be able to cut out pieces of walls for doors and windows instead of having to use a one-size-fits-all approach. This is possible in Unity, so I was hoping it might be possible in UE4. That does not lend itself well to the model->import pipeline.
Thank you for the information about UVs, though. Maybe there is something I can do to this end with BSDs that I can the convert to a static mesh and generate UVs for them. Halfway there!