I bought UberEats gift cards thru the UE app, and it did not code as UE, but instead some company called Launch (and no bonus dining category was triggered). When I applied the gift card to my UE account, the gc balance got added into my account and the Amex credits got used first. Because they get used first, as long as I exceed my Amex credits, then that gc balance carries over to the next month (as opposed to Amex credits which don't carry over). I'm not sure if I'm answering your question, but this was my experience with UE gift cards.