EngineerMom,
YES, you CAN use the standby line for Hagrid IF you arrive at 7 as part of early park entry. Not sure about jean's experience, but I did just the same - for the first time - yesterday. (Recent annual passholder).
Arrived around 6:30, made our way through CityWalk and queued up outside the park around 6:50, entered around 7:10 and made a beeline towards Hagrid, as did most everyone. The line was moving quickly even though the ride didn't start running until around 7:50. By the time we exited the ride, it was probably 9:19, so we waited a little under two hours, but it seemed to go by fast.
So, it's worthwhile to try this if you can. Again, I'm not sure about jean's experience... maybe they've only just started allowing the standby line in the morning with it being Mardi Gras and the spring break crowds. But, they absolutely allowed it yesterday. Hope that helps.
EDIT: Also, you CAN schedule virtual line passes through the app, just like Fallon, etc. I believe those QR code signs are simply for those who haven't already downloaded the app.
My partner and I almost scored virtual line passes WHILE waiting in line but talked ourselves out of it for the sake of other riders. In retrospect, we wish we had done it, just to ride the other seat. It's a great ride!!!