So today I took my car to the closest Genesis dealer (50 miles away versus 90 miles away where I bought it) as they recently EV Certified.
Provided them with a chronological narrative of all my previous attempts to resolve the issue and all the associated receipts. They said they confirmed the vibration, that the balance of all 4 tires was off by 0.5 ounces, and that they dismounted, re-balanced and rotated the tires.
The vibration is even less than before, but it's still noticeable. Probably 80% gone, although they claim it's completely gone.
Guess I could pressure Genesis to replace the other three tires, but I'm not sure I would be successful as I think most people would say at this point the vibration is minor. Still, after spending 70 grand, I'm disappointed. Want my car to ride like a new car

Also have a Kia Niro Electric with 20k miles and OEM Michelins that has had no tire balance issues.
I even considered replacing the tires on my dime. Not inexpensive, about $350-400 each, and there are few all season tires to choose from as this size appears to be rather uncommon.
What I thought was very interesting was that based on my zip code Michelin's website listed two places to buy the same replacement tire...Tire Rack and the local Costco stores. In the 21 inch size to fit the GV60 each of the Costco locations showed them as out of stock and unavailable to order, and Tire Rack website said "Out of Stock, on backorder, manufacturer does not have an expected due date at this time". Wonder what the story with that is.