Reimbursed with no issue for $90 AS charge to buy up to an instant upgrade fare class. I think that's absolutely the right answer under the T&Cs since the only thing I was paying for was seat in first in "U" (upgrade) class, but with some of the reports lately, I was a little concerned that I'd get pushback that a fare class change is technically airfare.

All my experiences with phone reps on this card have been great. If you're asking for something legit or at least reasonable, I think calling is the way to go.