Here is my experience from Tuesday Sept 8:
Left Riviera at 8:30 am and walked to the CBR Skyliner line. We arrived at the line at 8:45 and it was fairly long but plenty of people lined up behind us. The line started running just before 9:00 am to DHS. We alternated with a line from Pop. Anyone coming from Riviera, which didn't start running until 9:00, was sent to the end of the CBR line. We arrived at the park at about 9:15 and we were at Starbucks at about 9:25. Security was quick. We got our breakfast and ate it and then went to RnR. My DH and DD rode the ride while I stayed in that area to get a boarding group. I got Group 11 using Disney wifi. I was really happy with that. All the practice paid off!
Once they were off RnR we walked over to SWGE (the line for ToT was really long) and by the time we got to SWGE our boarding group was called. It was around 10:30. We went through part of the ride and then it broke down. We were told to stay seated and about a half hour later we were evacuated. They scanned our magic bands and gave us a return pass to use anytime during the day. We rode MFSR (about a 40 minute wait) and then we went back to RotR and it was running so we decided to ride it again right then. This time it didn't break down! It would have been better to not be stuck at a certain point in the ride for 30 minutes (kind of strange to see that section repeat over and over) but at least we were able to ride. It was stressful the whole morning and I was relieved once it was all over. Lines for the rest of the day were rather long. It seemed so busy! I would love to ride it again but I didn't like the stress of trying to get there early, get a boarding group, get stuck on the ride, have to come back later and hope the ride worked this time... We ended up changing our second day at DHS to MK. The wait times were much shorter there.
Anyway - success thanks to this thread. Thank you and MTFBWY.