I'm not a fan of racks on an A-Frame but seeing this picture and the way they installed them, I think I found a way to protect the roof windows when in storage. You lay a sheet of plywood or something else that's suitable and fasten it to the racks. I'm always concerned when a severe storm is coming and that dreaded hail damage. I need to talk to my friendly welding shop who does a lot of work with aluminum. He makes all his utility trailers out of aluminum and does a great job. Or, go to a boat cover maker and have a suitable cover made and fasten it to the racks. This would much lighter in weight and easy to store.