5 minutes might be too short, but some of those LL queues are long walks, plus you have the wait after merge. I'd anticipate another 5-10 minutes between entering LL and getting on the ride.
I wonder how long it would take to visit everything in DHS with LL, assuming a 5-10 minute wait for your LL return time, no wait before merge, but that the queue is full past merge, which Disney considers a 10 minute wait.
Some time on touring plans plus the Disney website says - 12 attractions, so that's 2 hours of waiting in the LL/lining up before the show. Plus 1-2 hours waiting for return times. An hour of walking time (from touring plans, assuming average walking speed) . About an hour of rides and 3 hours of shows.
That's 8-9 hours. You'll want lunch in there, and some stops for drinks/snacks, maybe dinner or some character greetings. That's a pretty full day to get your money's worth by using all the return times.
I really do think Disney is trying to create an experience worth purchasing. I don't think my touring style will be a good fit for
Genie+, but it might make a lot of casual visitors less frustrated than they were by FP+.