I'd like to see what a 2019 F250 Limited 6.7L diesel has for payload. I bet it's around 2k. The best source for that info is the "tire and loading information" sticker inside the driver's door. IN the real world, with any decent size 5er, he'll be over GVWR.
I found (via google) an image of the sticker from a 2019 F250 diesel Platinum. Payload was 1790#. His will be similar. Add in passengers, and a 5er hitch, and some misc cargo and you're going to be left with about 1100 - 1200# for pin weight before you max out GVWR. That's just life with a 3/4 ton diesel with a 10k GVWR (which is the max for the class of truck). That's in the "half ton towable" 5er class. Cougar makes a "half ton" series of 5th wheels. Their pin weights are 1300 - 1500#.
