Had one on my previous truck. Worked fine, plenty of room behind the hitch for storing the leafs. I was able to close with the hitch installed. In my instance there was enough room behind hitch where pulling the strap allowed the panels to go over the hitch. Don't remember that hitch height so can not tell if it would work for you. I believe the plate on the hitch was 17" above the bed. You have to climb inside the truck to attach the strap for keeping it open. Was towing a short distance from home and did no attached the strap. The wind blew the strap between the bed and cab. It twisted around the drive shaft and sounded like a cannon when the strap broke. Eventually got to where I never closed it.
It was not water tight but did a pretty good job of keeping most of it out. Installation correctly is important.