I don’t see us getting one again.
On our first stay, it was included in the UK package we got, but I found myself always trying to work out which meals to use it for and which to buy OOP, so as to save the credits for things like character breakfasts at Cape May, which we loved (we were staying there). Too much hassle.
Now that we’e DVC members, we cook breakfasts in our room and a few other meals too, never going to get value out of it …
Except - Last year we got it for 3 nights over Christmas itself. We knew we wouldn’t get to Publix in time, it was the first part of a split stay and we booked Chef Mickey, Crystal Palace for dinners and Ohana breakfast, and a BOG breakfast. Definitely got our money’s worth in terms of what we ate, even without worrying about where to use the remaining QS credits. The mugs lasted us all 2 weeks too, added value there.
Unless you know you’re doing a character meal every day, or sharing between 2 rooms, the chances of you coming out ahead with the dining plan are small. Some people can make it work though. Good for you for trying to maximise value. Can’t help with the spreadsheets though.