On my cruise last month, I was told to hold on to my gift cards. Fortunately, I was able to apply them to my account over several days and no one was ever in line at guest services, so no taking up other people's time. The CMs weren't busy when I approached the desk. I'm not sure how this would work if I had a high number of cards (i think I only had 6 total). I used them for extras, not to apply to the total cost of the trip because I don't want to get stuck with Disney gift cards that total over thousands of dollars.