We have used DDP 5 times now and have split many a TS meal. Inc. at Narcoossee's (4 adults ordering 3 meals). Never had an issue with it, in fact the wait staff seemed to understand it without explanation. We have never eaten at Beaches and Cream so I can't comment on that one. Sometimes It will be my DM and I sharing and DD9 getting her own kid's meal, or other times DD and I would share. This allowed us to go to a few more restaurants (and some 2 TS) that we wouldn't have otherwise. I have also paid OOP for DD9 at CG where she only wanted the pizza and didn't want appetizer (when it was inc.) or dessert-I think she's the only kid who doesn't like the Sushi Rice Krispies. Most of the time she's happiest with a bowl of vanilla ice cream.
That trip though our great waiter gave her a free birthday dessert anyway.
The only time we had an issue with sharing was the first time, Jan. 05 (paid for it) when it had just started. We shared a meal at Spoodles but were still charged for 2 A and 1K. Turns out that at the beginning (of DDP) the credits you were charged was based on how many non-alcoholic bevereages you ordered. After we figured that out if we shared a meal (I remember we did this on same trip at 50's PTC) we would only order 1 beverage for the adults and the other would get a water.
Of course, if my DM had a glass of wine, it was OOP anyway and then we would be charged the right amount of credits.
Apparently they don't do this anymore since we haven't had to worry about how many non-alcoholic beverages we order. Disney has worked out a better way.
This year my DD will be turning 10 during our trip so she will be an adult. I can foresee that we will undoubtably be sharing again (2 adult meals for the 3 of us) as well as there will be times when she'll want to order the kid's meal and I will pay OOP to save that adult credit for a better use.
Just like at home when we share a meal, we do adjust our tip accordingly.
If you have any more questions, feel free to ask. Like I said, we've used DDP 5 times now, with this Sept. being our 6th.
Happy eating all!