This sounds complicated. What are the chances Ford puts out some guidance with recommended trailers/campers with remaining payload weight of towing capacity with each trailer/camper they recommend?Say what? Why would payload be deducted out of the max towing capacity? The way you're describing it, it has a max towing of 3500lbs but then for example subtract 2 adults (300lbs) + 2 kids (120lbs) + fuel (126lbs if 18gal) + gear (150lbs) = 2,804 max tow capacity.
Shouldn't it be:
GCWR less GVWR = towing capacity? or GCWR less (curb weight + weight of passengers, fuel, and cargo) = towing capacity?
GVWR less curb weight = max payload (people, fuel, gear, additional options/equipment add-ons that are supported by the vehicle's suspension & trailer tongue weight)?