We just went in June on the basic
DDP with our family of four. Our daughter is ten also, and has special needs. She eats foods very similar to your son - soft foods, or things cut up very small.
Since you pool credits for the room, we were able to use her TS credits to go to a couple of signature meals, etc. When we were at these places, we just bought something for her out of pocket and explained to our server that we weren't using the dining credits for her meal. (I hated the thought of using 2 TS credits for an order of mashed potatoes or mac and cheese.

) Every single restaurant was accommodating. Our server at the Yachtsman Steakhouse didn't even charge us for her side order of mashed potatoes and gravy for her meal!
We stayed at Coronado Springs and ate a lot at the Pepper Market for QS meals. Their portions are HUGE and we were able to share many meals with her there. For example, I would order a breakfast meal and she would eat the scrambled eggs and I would eat the rest of the food that came with it. Or I would order mashed potatoes for a side dish with a burger and she would eat the potatoes.
Plus, we were able to use many snack credits for foods that she could eat such as yogurt and bananas.
I would definitely get the DDP again. I think we made great use of our credits for our entire family. We did have to pay OOP for our daughter for many meals, but side items/kids meals are pretty cheap.
