I'd say first of all to not try to breed your plants, just try to grow one or two quality females. I'd also say to LST instead of use a screen, and if you LST you can grow one bigger plant in there instead of multiple smaller plants that may get too crowded. You can also do what I did, which is flower at two weeks (I actually flowered at 1.5 weeks), and let your plant grow normally without LSTing, and it shouldn't grow more than a couple feet. And later on you can tie it down so that it bends somewhat and makes use of the entire grow space, and the lower buds on the side facing the lights will grow bigger.