Mine are not metal grates like you are describing, but I fully agree that this is one of the dumbest things they do, and ALL the trailer manufacturer's do it. And you're right, eventually those little.screws will strip out.
My panels in my 5er are thin wood covered in matching carpet in my pass thru basement storage. I put small hinges on them and hold them closed with a metal catch and a magnet. I bought the catches and hinges at Lowes in the cabinet hardware section. The screws were longer than the thickness of the wood panel. SoI installed them to get everything mounted correctly, marked where the screws needed to be cut down to and nipped them off. I put a dab of wood glue in the screw holes of the panels for more hold and installed the screws. The magnets needed a small piece of wood added to the wall to make everything work. Both panels stay closed nicely too.