UPDATE: Shop has determined that all four of my new Cooper tires are all out of round, so will be seeking replacement from the other shop I bought from and that installed them... Will see what they find out when I bring the vehicle back to them for their assessment.
Note - I have another set of Cooper tires on my Ram, and have been completely happy with them, so hoping this was just a bad run, Not bashing that company at all...

2014 Explorer Limited, 3.5l non-Ecoboost. 4WD/AWD. Has a vibration when driving I just can't locate. Quality new tires all around (Cooper Adventurer All Season) balanced, new rotors and pads (Powerstop Z31 set), fresh lifetime alignment done at Firestone. Had one wheel fixed, had a dent in the back like it had hit a curb or something. But, vibration still occurs, especially at speeds above 35 mph. At 70 on the highway, it can make your butt numb. Any ideas on what to check next?