UPDATE:
They tried the UV method. It does NOT 100% remove the yellowing, it makes it faint, maybe about 20% of what it was, but if you are looking for it you can 100% see it still, especially if you turn on sketchpad so the screen is white.
The manager tried to argue with me that it was reduced, but I pointed out the arbitration agreement stating it must be repaired.
They are now trying a second time I believe, which I don't think will make any more difference.
Ironically, trying to cheap out on the screen has cost them significantly more then just replacing it:
4 days of model s enterprise rental (dropped off on Friday)
$600 in uber credit (switch to this through Saturday)
Plus whatever arbitration costs them.