Exactly Grit!! I schooled your tire jocky buddy (C Rer), on this very issue. I know tire max load may be reached at near door sticker pressure, but with heavy tongue wt, more air is better, usually tire max pressure, as marked on the sidewall of a 1/2 ton truck.
I challenged him, to borrow a trailer, since he didn't own one, take it for a tow, with 1K+ hitch wt. Now air his tires to max pressure (51 psi, IIRC) take it for a tow, and report back. He did finally admit, that some more air might be better, but I don't think anyone trusted him to tow their trailer.
I am referring to max sidewall pressure on truck rear, and a bit more than door sticker air on the front of a 1/2 ton, when towing a 7K+ GW trailer.
Jerry