This is an aside but reading that last line made me think you’re going to have to run 60+ psi in these tires like a HD truck because of the weight and 10 ply plus
I am not sure of the exact tires for the Hummer yet, GM stated they are not off the shelf tires, and are special for lower rolling resistance while maintaining the traction, I hope they are not 10 ply, as that is going to make the Hummer rough riding on city streets, and if you remember back to the test drives, when they take it fast over the RR tracks, and on the washboard roads they tires were not bouncing much which makes me believe the pressure is lower then 60 psi. I think GM will run them about 45-50psi for normal use and 25-30 psi for off roading (possibly lower for rock crawling, which is where it would be nice to have beadlock wheels)
Remember Hummer EV is a Unibody, and Unibodies are much stiffer then typical body on frame pickups which flex in several areas through the chassis, stiff tires, and stiff chassis, could make the ride no fun? Another thing I notice in WTF mode, those rear tires pull right down under hard acceleration, as the weight transfers onto them, another sign of lower pressure.