You know if they wanted to increase the ride time, they could probably get rid of all those random launches in the middle of the track and turn the launched lift into a lifthill.
For what it's worth (which is very little at this point), L.C.A Studios over in Japan has been observing the dispatch rate of test cars past the Temple facade visible from the Potter area, and has calculated a hourly capacity of 1144 an hour, which seems a bit high, but definitely clears something like 700 people per hour.
Of course, as they point, these are just calculations with available data, and we'll either just have to wait and see what actual capacity. Or we could try to make a smug point in an arbitrary argument about a different attraction by pulling data out our butt.