On the DxDDP the credits are all credits. You use them interchangeably for CS meals, TS meals and adult vs. children's meals. The credit is the credit. If you want to use those credits to feed someone else, you can. The language that prohibits that has been removed from the brochure, so it is not an issue. When we make the decision to use this plan we look at the overall dining schedule we have, and run some numbers. Normally we do order appetizers, but we would share, same with dessert. The plan simply allows us to order more freely than we would give ourselves permission to at other times. Anyway, I build a sheet, enter the restaurants and credits we would choose, look up the entrees, etc and use the figures that my family normally orders.
The too much food argument is not one I worry about. I calculate what we would order and if it's close I use that as my guide to which plan to get. TO be honest, it is a non issue if my DH joins us...I learned the hard way. Also, if your kids do like the adult menu, this may be a good time, when they are under 10. I think the value is better for DxDDP at that age, and even moreso if you have someone joining you who needs a few credits at dinner.