I have a 2011 F-250 diesel and a 36' fifth wheel. I would like to somehow cover my truck bed as much as possible while towing with a soft cover to protect items in the truck bed. This would require an access hole for the hitch.
I think your in the wrong spot lol. Maybe a mod will correct this?
Back to the question! Iv seen a truck with a 5er and a Reese Sidewinder hitch. This basically moves the pivot point of the trailer from the hitch to the pin box. Its actually for short bed trucks but I don't see a reason a long bed truck couldn't use it. The truck Iv seen it on had a hard cover and he simply cut out a hole the size of the pin box. Since the trailer now pivots at the top of the pin box and not the hitch, 90% of the bed is still covered by the tonneau cover. I hope this makes sense lol. Maybe I can get a pic.
If you don't want to spend the money on another pin box, then I don't see why you couldn't modify a soft cover to fit the front half of your bed. Of course, if it rains, the water will slosh forward and get the bottom of whatevers in the bed wet. Some ingenuity could possibly fix this? But the same is true for the above mentioned idea as water can get in the hole where the pin box is... Some experimenting ought to yield you the results you want!