I think it must depend on who is working, when we were there in Nov we could not trade the drink for a dessert when we asked... but we COULD use 1 quick service meal to get a soup and 2 desserts (so trading 1 quick service meal for 3 snacks essentially- which I know some places you can't, but here we could no problem..at least that day)
Ps- pretty sure we did that at BOG lunch too with potato soup & 2 desserts counting 1 of our quick service credits, but I can't remember 100%. My daughter doesn't care for any of their sandwiches .