I just did the math, and the DP definitely will make sense for us regardless of what I do for the 4th TS option, which is a relief!
So far, not including tip, costs break down as follows:
Akershus breakfast (1TS each): $62 adult / $39 child = $101
Ohana brunch (1TS each): $53 adult / $33 child = $86
Roundup lunch (1TS each): $49 adult / $28 child = $77
2 resort mugs: $49
Total cost: $312
I still have 2TS, 8 snacks, and 8QS credits to work with, and I only paid $394 for the DP. So, as long as those all cost more than $82, I will come out ahead on the DP for my me and my daughter.