So if I put a plastic panel on the top that was the same size as the RHP and made a frame to hold it in place on the screentop, would that work? Can an RHP be safely mounted directly on PVC? I really don't understand how the temperature rise on the non-lens side works. They say to put nothing within 6 inches of the lens, which is great, but they don't talk about how the mounting side is heat shielded or anything else.