Good information also. I ordered the aluminum extrusion and vinyl batten to install at the midway point between the two existing ones that are on the ceiling in my bedroom area. I am thinking if the unsupported distance is shortened from 48" to 24" maybe it will be supported better. I plan to stain some shoe mold and install it on both sides of the bedroom area to dress it up and also hold the vinyl better.
I do have a question and have also posed this to Customer Care. What length screws did you use, I want to make sure I don't get into any wiring that is installed above the ceiling, I am not sure how much Styrofoam is left after they route it out for their wiring paths.
Your idea sounds interesting, where did you get the extrusions and battens?