We just returned also, were in the parks Sunday, July 11 and Monday, July 12. We had a lot of fun and did all the attractions we wanted, many more than once, but we also waited wayyyyyy longer for attractions than we ever have before and longer than we would have ever waited previously. We definitely missed MaxPass or any sort of FP system. Like you, we found wait times would jump up considerably higher quickly, sometimes while we were already in line. Example: MH stated 25 on the app, we went to it and there were people everywhere. We knew that was not just a 25 min wait and sure enough, the CM announced it was now a 50 min wait. Same thing happened at TSMM. We were also pleasantly surprised that some posted 50 min waits were more like 25-35. It is all very random right now in my opinion on how it may all go. My advice to anyone visiting the parks these days is to just go with the flow because you do not know how it will actually go! We also experienced MANY MANY MANY attractions being down. On Sunday, our DCA day, there was a time when three major attractions were down at the same time.
Also, totally agree with you about the Mobile Ordering. Not great right now. We were most successful at Red Wagon for a corn dog. The order time and pick-up were almost simultaneous. The worst was for Dole Whip, such a long wait and then we were required to wait in a lengthy line to pick it up. I experienced the exact opposite of that in Dec. 2019.
My #1 tip will always be to be up and out early each morning - be at the gate about 45 mins before park opening. You will never regret it. Being at the front of the rope is always worth it to our family. We had fun for sure, and I believe everyone is doing the best they can.