Explorer bumper is a concern for sure, as i had before and if you learn how to drive it without getting too ambitious following some offroad modified cars its fine. In desert in extreme weather it also heat up a bit if you run longer at higher revs, thats wht show the AT light also and effect transmission too. If AT light comes on, give rest and then drive.
I have done six months in cool to moderate temp and never had AT light come up. Only front bumper was a concern when i climb up the dune. If you lift the car then on road ride quality and comfort will get affected. So i wouldn't advise that unless you have bought this car only for desert and have other car for road for office run / family run.