Interesting, I've never heard it was good for a plant to become root bound that far before finishing, I always assumed the buds wouldn't fill in properly if they ran out of dirt early.
My only suggestion would be shorter flowering time plants. Filling a room with plants that yield well and finish in 49 days compared to plants that finish in 60-65 days. You can get in 1-2 more harvests per year. I would much rather empty a room and start the next cycle than wait for a 60+ day finisher.
I have a chemdog that finishes in 49 days and is covered in crystals, and is also nice and dense, so the weight and bag appeal is there too. Vegged for 1.5 - 2 months I have yielded 7oz off one plant. Even if you only average 5oz per plant and do 12 in your room... that's 60 oz (3.75 pounds) you could easily hit the 4 pound mark an earlier poster mentioned. Unfortunately the chemdog I have was given to me as a clone and I don't know the breeder it came from or I'd let you know.
I agree with Phil about 4 plants under each light, that's how I'm doing it too. If the cops show up, 12 plants sounds better than 20 plants. If you take a bunch of clones shortly before flipping your room if you have a 8 week finisher that should end up with about 10 days for the clones to root, then vegging for a month and a half while your bloom room finishes, then you have nice size plants ready to flip right as your bloom room finishes up.
my $.02
BTW if anyone has suggestions for a plant with little to no stretch, that finishes in less than 50 days with a great yield and uplifting (non couch-lock) high I'd love to hear about it
I like my chemdog but it really kicks your ass, spaces you out more than I would like for daytime use.