1050 on 7” wheels

So I’ve gone and got a set of 31/1050-15 Kanati Mud Hogs and mounted them on 15x7 wheels. Coming from a set of General Grabber X3 33/1050-15 on 15x8 wheels I figured I’d need a little less air pressure. I ran the 33s around 32-35psi to get a good tread mark and wear. These 31s are a different story. I’m down to 26psi and still haven’t worn the outer teets off the outside lugs. This is 600 miles at 30psi and 300 miles at 28psi, and 900 miles with 26psi. Logically I would go down to 24psi and see if the wear is more even. I do have a 5th wheel/tire that hasn’t seen pavement yet and May just rotate it in early to see if 24psi will be the magic number.

Really hate to go any lower or do these tires just wear different?