We just got back last night from the parks. We were there Monday - Wednesday and this was our experience.
We stayed at the DLH. You would think 9 am was a nice late start but by the time we got up and head breakfast, it was still a struggle. Fortunately, security lines are not too bad there. We left at 8:30. Got to turnstiles around 8:40 and in the park at 8:50. They are not taking photos so people were getting through pretty quick. We went by the flagpole. Lots of people in there just waiting. Did a speed test and it was good so we stayed. That day we were all successful getting the red button as soon as the time switched. DS20 finally made good use of his many many wasted hours on his phone and secured group 16. We are called up by 10 am. Line was a little slow but we kept moving and it was great!
Tuesday we had MM at DL but didn't make it into the park any earlier. We checked into the monorail and rode it in and got there around 8:50. We decided to try from Fantasyland to try to get back to Galaxy's Edge and ride MFSR. Bad idea. The speed test was much slower where we were standing. We were by Small World which was another mistake. We didn't have much time to move so we went with it. None of us could get the red button once the time changed. I heard a few cheers around us but not near as many as we heard at the flag pole. DS20 finally got through with backup group 81. That was disappointing but they moved at a pretty good clip all day long so we were optimistic. Of course, until we got there to ride and it was down. Waited over an hour and finally decided to head back to the hotel. Stopped at the ice cream shop on Main Street and saw that it opened back up. Walked back there again and it was down again. A lot less people were waiting around at that point. It was cold and we had another day ahead of us so we decided to leave. We were back at the hotel by the time it opened agin (6:30 ish). We decided it was not worth the journey back. (we went back there 5 times that day!). They ended up getting up to group 120 I think. I assume because it was cold and kept breaking down so people just gave up and left.
Yesterday we left the hotel at 8:35. We got into the park around 8:50 again. Speed test not as good by the flag pole so we walked back by the entrance (not outside of the park) and it was quite a lot higher there. I think 80 vs. 25. We waited with lots of other people and DS20 got group 16 (they started with group 8 so that was equivalent to to group 9). I could not get the red button to load before he secured the pass. So it questions the theory of closing everything out and restarting. I did all of that and it didn't work. He probably hasn't closed his apps out since he got the phone! Anyway, they started with group 8 and we were called up around 10:00 again. The line moved at about the same pace. Probably 45 minutes to get through.
Overall 2 out of 3 days were a success. The second day was frustrating on a number of levels. Since we did not get there early enough to do anything for EMH, we really should have just scanned or tickets at the monorail, exited and walked down to the esplanade. Once we secured our boarding passes, we would have decided which park to go to based on our expected return time. With 81, it was a waste to stay at DL because it was already very crowded. And the line for MFSR was 45 minutes as soon as the park opened because there were tons of people already waiting. So we weren't the only people with that idea. I also think we would have got better than group 81 had we waited up towards the front where we know the connection speeds are better (at least for us). And it would have been a much more efficient use of our time because it was a long walk from Galaxy's Edge to TSMM!
FWIW, we are AT&T. DS20 used an iPhone XR and got our Boarding Passes all 3 days. I have an XS, DH has an X and DS18 has a 7.
A few other notes. I am not sure this was ever mentioned but there was a lot of speculation/discussion as to why they close the ride early. It's because they need to give people time to return to get on the ride. He said they would call the last group at 7:45 to give them time to get back before the park closes at 9:00. Not sure why I never thought about that but it certainly makes sense. And they do not notify you when the ride is down. it says Open but you walk back there to find it closed. He said keep checking to see when they call the next boarding group because that would indicate it opened back up. Also, I screenshot all of our passes because they were expired by the time they reopened the ride but it really wasn't necessary. You could still open them even after the time expired and we were told that they would still honor them because they knew the ride had been closed. Not that the screenshots hurt. But you can still access the passes which I think is good to know. The only people who were actually issued return passes were those who were already on the ride. They were told they would enter through a different line once the ride opened back up so they would't have to go through the VERY long general line. And I did not receive a notification that our boarding pass had been called. I only knew because I kept checking the app. I think my son received the notice. Presumably because he was the one who go the passes? It wasn't a big deal. I imagine most people check constantly just to see how close they are. Just don't rely on the push notification.
I know that there were frustrated people who didn't know what to do but most seemed to take it in stride because they had multiple days at the park. We were happy to share info. with anyone we spoke to about how to link tickets, do the speed test and be ready because they are consistently gone in the first minute. One lady I spoke with had 7 people in her party (all friends) and they didn't know anything about linking tickets. They would have tried the next day and possibly got 7 different groups because they didn't know to do it all together. Or they wouldn't have got one at all because they were trying to figure out how to get them together. So I was glad I could help her and I hope they were successful. I honestly would have been very ill prepared if I didn't spend so much time reading this thread so I am thankful for everyone sharing their experiences. I hope my experience will help someone else!!