Depends on the year.
I was blessed... the '13 2500 has a "Light Load" switch that "dumbs down" the pressure alert point from 60 fr / 65rr to 60 fr / 45 rr. MUCH better ride, even on the already plush Power Wagon.
That said, I ran the stock BFG's around about 5k miles last summer aired down to 25 psi ALL the time (other than extended high speed towing). This is because I got sick and tired of sweating out and breaking my old knees and back airing back up with those wheezy ass low-volume gas station pumps every time I "aired down" to go down a long stretch of wash board road, or through some flour like blow sand that seems to be everywhere I want to go out here.
Of course, the TPSI went off with every re-start, but it was worth it. And, much to my surprise, the stock BFG A/T KO's never did heat up, wear funny or self destruct!
My buddies 2014 Power Wagon DID NOT come with the "Light Load" switch, and it makes him crazy. His too came from the factory with 90 psi all the way around. I told him what I was doing, and he thought I was a bit nuts. The new PW's come with different tires, so as usual, YMMV!!!
But, I told him to air his down to the minimal number on the factory door jamb sticker and deal and go from there. But, you want a better ride, no "wheel hop" off highway, and a 100X improvement in ride, air those suckers down. Just be prepared to ignore the warning chime, etc.
But, for everyone's safety, air all those suckers back UP before throwing a load in it or running freeway speeds (or both) up a twisty road.
And those, are my two cents...