You should at least have gotten a T-shirt out of this that says “I got the shaft from Ford.” The good news is, since you went to a dealer, surely they used the proper lube.
But seriously, the “damper” on your list is not the dreaded “guibo,” the subject of the recall, rather it appears to be a damper for the rear axle. The question is, what led them to determine that damper was bad, and a true “gold-star-deserving” dealer, might have handled the repair/replacement of the driveshaft itself differently, given that there is a renewed recall and Ford is really on the hot seat (was the service after the latest go-round on this? On or about Oct 31, 2019). These things have been in a “emergency-non-emergency” status for, what, nearly 2 years now (or has it been longer?). NHTSA isn’t breathing down Ford’s neck about a vibration nuisance, there is a real safety issue involved.
It would be interesting (or crucial) to know what the dealer 500 miles away actually did, or didn’t do. Did your local dealer use this logic: surely the other dealer fixed the guibo, but problem persists, so it must not be the guibo, so let’s just start replacing a bunch of other parts to see if we can accidentally eliminate the problem.
While I know only a little about that rear damper that was supposedly replaced, what would also worry me is that, the new symptoms you mention sound like what it should be “damping out.” Did they F that up too? Or is the rear diff going out too? THAT might truly need to be on your nickel.
Yeah, Ford may have to pony up, but you better have your ducks in a row. And yes, you probably need at very least the Regional Tech Service Rep involved. It would be super if they went “above and beyond” for a change, and fixed you up completely.
P. S. Might be a good time to NOT have oversized wheels and tires on this thing...or other drivetrain mods.