There are very few restrictions on the plan. "add ons" are items like add some BBQ Shrimp to your steak meal or something of that nature those would be excluded, but you could have them and just pay OOP.
Items intended for 2 or more people must be shared among 2 or more people to use credits for, and some really expensive sushi appetizers are considered your entree if you would like to order them. Other than that there is not much to prepare for --just double check with each server if you have questions or are unsure many are happy to guide you!