I posted this a long time ago.. but for mappers.. making 1 room can be incredibly detailed let alone a whole map, and since you can select multiple and rotate a giant chunk I thought:
Why not merge 2 files? Just do vertex, face, and prop lookup on the files and merge..
That way mappers can make separate rooms in files and just merge them to a master that they skew it around and place & fit it. Even sections like hallways, lighting configurations, etc. Maybe perhaps an export function too?