I did the QR code thing but I have to do it every time I log on.
Assuming it's the same as the setup enabled for mod accounts a while back, you'll have to log in again each time if you're switching devices, browsers or virtual machines, as well as if your security or browser settings prevent the "stay logged in" credentials being saved.I entered an old email addy, got the code stuff and have not had to log in again.
All in all it took less than 2 min and zero problems.
I dont know how the QR thingy works, but with mail you have option remember on this device (or similar) for 30 days. Make sure that is checked.