Knna,
I have an idea that I have also been working on in order to get more growth in Z-plane. This would also help if you are wanting to grow taller plants.

I have a design for a vertical plug-in module that drops down below the top of the canopy. The problem is with cooling. Heat sinks block too much light, plus they are dissipating heat onto the plants.
My design low profile water cooled module, where I am mounting emitters right onto a piece of U bent copper tubing about 6 inch long. I have only built one and it seems to do okay. I don't know how ganging up mulitple units will work.

Another issue is that you would have to reduce top lighting in order to keep within your watts/sq. ft. parameter. So the question that needs to be answered is "where will a watt of LED power need to be positioned to get the best results?" On the top?, On the side? or a combo?
I hate to introduce more complexity into the array if it is not beneficial