That is why I had mine set at 1.75" one notch from the top.
And it might also depend on the suspension payload package. When I bought mine I was going from a 3/4 ton Suburban to the 1/2 ton F-150 and made a point of getting the max towing package and I think that also implies the max payload package as well. For reference here is my truck last weekend with a pallet of mulch in it, probably about 1,800 pounds, probably pretty much at max capacity:
ETA: when I put something like the 600 pound ATV back there you cannot even see a difference.
ETA Again: with the 2015+ it may be different, but on my 2014 if a truck has the big mirrors it probably has max payload. When I was buying it there was plenty of room for confusion, I kept going through build and price, and couldn't find the big mirrors. But when you went back and specified 3.73 then boom, there are the big mirrors and integrated trailer brake controller.