depends on your technique i always top the plant out at 2 foot when side arms come top them out at 6 nodes keep bending arms down you can achieve 40 arms all the same height and get even light allround you can get 40 oz plus this way
you have to get thermal insulated mylar leave space between walls of shed and roof so air can circulate only prob is extracting hot air i no people who got caution im in england with 25 plants some were cuttings best to stay below 10 to be on safe side