DH and I have all of our ADRs, however, we've been thinking about using the option to trade a TS for CS for a couple of our less favorite restaurants. Do they swap your credits at check-in or do you ask the CS CMs to use a TS credit instead of CS?
You just ask to use a TS while you are purchasing the food. I don't know about most places, but one of the CS restaurants (I think it might have been Backlot Express) had a sign indicating that if you used a TS credit you also get a free lanyard and pin set or two extra snack items from the menu.