HankFard

I found on mine that one or more flat washers were called for to make final height adjustment and avoid the clamped down appearance you refer to.. My washer is on the bottom. The two aluminum spacers are both at the top. I have tried several combinations and this works best for me.
I do not get any visible movement of my spare tire/wheel while driving, but on some bumps you can hear things creaking a bit. The rear door does "oil can" a bit (front to back bounce) if you close it too fast, so I always take care to close it with least effort necessary. Adjusting the rear door latch can be a big help too.
I recently readjusted my bumper according to the Exp-One instructions, and then put a torque wrench to the mounting bolts. That did help quite a bit, but the bumper bolts can be a bear to get at, so have patience.