I do separate the plants out, but all in the same room. Tallest to the back walls, shortest in the middle and the rest spread around evenly. Normally, under HPS, plants fighting for space will grow taller. Under these LED's, as you know, it really doesn't matter. There's enough light spread evenly around and strong enough it's almost impossible to grow things tall.
The late finishers sometimes get moved to another room at the end of the grow, so I can start the cleanup for the next crop- but the days of utilizing 2 rooms at one time is probably over. The wife won't allow it, I'm generating plenty out of the 1 room and having too much smoke around the house (and more plants) probably isn't a smart thing.