For whatever it is worth- my F350 squats about 2" under 5000 lb camper weight.
Using it as a crane on picture above, the weight on the arm was squatting the truck all the way to axle bumpers and I had to put 4x4 under to gain lifting height.
Meaning a little bit more and I would lift front axle off the ground by applying weight on the stinger.
Never have seen any signs of stress on Ford hitch and I know metals.