If the aluminum tube is flexing too, then I would try to see what could be done to stop that. Maybe a piece of angle attached yo both sides? Better quality aluminum that won't flex as much? I think the panel would pull back down flat when you reinstall it for the most part. But you may even be able to make a new one that has some ribs built in on the bottom side to help stiffen it too if you're good at fiberglass.

Sent from my SM-G781V using Tapatalk