I have experienced the same thing -- the more weight in the back, the worse the wandering gets (passengers in second row and gear in back).
My JLUR has Mopar lift kit control arms and a caster of about 7 based on a recent alignment. Total toe has been set to .34 as per FCA spec. My steering...
It can work but you have to remove the bumper support bracket underneath the plastic bumper . That piece is added support, so if you are doing a short term install, it shouldn't be a problem. I am sticking with the plastic bumper, so i want to keep that piece in there.
Selling Mopar hitch for steel bumper (Mopar model 68240905AA). This one has all four welded nuts).
I would also trade for the plastic bumper hitch which only has the center two welded nuts. Will ship at buyer's expense, but prefer local.