Probably could make a custom brush that could do this. The only hard part would be filling in the rooms. Not sure how that would be done.That is awesome - I want that pen for PS now!
It has been a while since I did regular PS work, but it does seem to be beyond the functionality of simple pen. The way it doesn't add the hatch when your cleaning up the rooms is, as you mention, the hard part.Probably could make a custom brush that could do this. The only hard part would be filling in the rooms. Not sure how that would be done.
My guess: textured brush (with the texture grid matching the size of the underlying grid) and a stroke layer style (for the black edges) and a shadow? style for the hatching?Probably could make a custom brush that could do this. The only hard part would be filling in the rooms. Not sure how that would be done.