Have you considered bending your plants and staking them down? I've also read about snapping the main stem slightly and letting the plant heal itself. All the nodes up from the snap will then flower into colas. You could also use a net for your screen and train and tie the tops to net horizontally. That way, you would probably triple your yield and the entire canopy should remain even. I plan to try several methods until I get one I'm happy with. With LEDs, you have to have a lot and get them close. I'm going to try to avoid bushy plants with a lot of fan leaves.
thanks Lucky for visiting my new thread on building an LED closet. I'm very encouraged by your UFO results. You are getting nice yield for that tight space. I'll be watching.