Multiple delivery order and showing them as one order is really bad one and obviously this will be opposed by deliverers. Moreover the first one also has the reason to oppose as you already have mentioned that sometimes we have to remember who treated us well or not. I hope they will change at least these issues and will make change in app and policy.
Using two you have to be attentive. If you run two at the same time better ensure there going in same direction. Once they change things it's rare they bring back. If it makes the company more money it's a wrap