In theory, that is correct, but that early in the morning it will not be distributing FPs that late yet. You are more likely to see them for 10:30-11ish for RSR. Evening hour FPs tend to start being available around 12:00-1ish if it medium to higher CLs. When I went last summer, I watched the days prior to going on the app to get a rough idea of when I would need to pull a night fp, as an evening ride on RSR was a high priority.
As far as only being able to hold two fps through MaxPass is incorrect. I have been able to stack as many as 4 fps before. It really just depends on the timing.
As for the fp return time variability, it depends on the fp return time window. If I pull one for HM for 2:15, I can pull another fp at or after 2:15, even if I don’t tap in yet. So I have pulled a fp for HM while waiting in SB for pirates at 2:00 for 2:15 for HM, then a BTMRR at 2:15 for 2:40 and then pulled a SM at 3:00 for 5:05, all before I tapped into HM at 3:10. I am sure that is confusing. It will make much more sense once you start using it.