Someone with a little more dining plan savvy might know the answer to this question...
I know that every one on any given reservation must be on the dining plan, or else no one can be on the dining plan. But does that mean that everyone must use their credits when they all eat together?
Hypothetical, 3 people, 2 parents and the child of a 12 year old sit down to eat together at a table service restaurant, but one person isn't terribly hungry and only wants an appetizer and soda. Unless the restaurant in question is a buffet, where it's pay one price (or one credit) regardless of what you eat, couldn't that family ask to use 2 table credits for the 2 full meals, pay for the appetizer out of pocket, and then save the unused credit for a meal later, or use it towards a Signature Dining meal?
If that sort of thing is possible, I wonder if that might be a way to go for the OP - put the 10-year old on the dining plan as an adult, but pay for his meals out of pocket, and then keep using his unused table credits for Signature Dining Credits, and his counter service credits for other meals where necessary. I know that Disney portions are pretty big, and I don't think I'd want to eat 3 table-service meals a day, but when we're on the dining plan we still tend to pay for a counter-service breakfast OOP (maybe one or two breakfast buffets over the course of a vacation), counter service credits for lunch and table-service for dinner.
And on the flip-flop, if the OP's son decides to start being adventurous, you already have the dining plan.
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