^Yes, correct, even max rated pressure is not “that” stiff on a P, C or XL rated tire if a half ton is really doing work.
I have been known to, on more than a few occasions, air up 44 or 50psi max truck tires to 60-65 psi when carrying heavy loads or big trailers. It works and it does the trick.
I would have never believed the tires would hold up, but I once got upset with my Area Manager because he wouldn’t authorize me getting a 3/4 ton company truck. I had a very nice new 1/2 ton but got a couple projects that required me to be towing pretty heavy, frequently. So I shimmed up a set of Timbrens with a couple extra washers under the bed of that F150 and cranked the little 44psi tires up to 65 psi or so. Enough to keep them from squatting under the weight I was carrying and pulling. Figured I’d destroy those tires in short order. To my surprise, 4 months later I was done with those projects and let about 25psi out of the tires so that it didn’t ride like flintstone wheels and they were none the worse for the wear, other than the tread was wore out at about 25k miles.