I know no one could give me a straight answer on this but I figured out how to split a mobile order using both CC and DDP.
Go to the individual item and click modify order. Then you will payment options at the bottom. It was quite simple really.
I was glad I figured this out because I was out of QS credits and it seemed like it wanted to use DDP anyway and I was scared it would take TS instead. Anyone know what would have happened? Anyway, I changed the meals to CC and used snack credits for drinks.
Also of note, a CM told me that at busy times they disable mobile orders to limit it so Ofer we’ll ahead to avoid this situation.