AYFKM, Apple? The best answer you can give us here bears on "If you enter your iCloud Security Code incorrectly too many times?" How about *ZERO* TIMES? There was no prompt, no code, not ANYTHING that popped up after I dutifully went to open my other device and logged in to iCloud. And this was all supposedly set up and DONE, 24 hours ago when I reluctantly signed up for 2FA.
If this isn't absurd enough in itself, during the process of navigating to get Chat-help via iCloud, I had to 2FA-identify myself on my PC -- using a code that Apple sent TO MY LOCKED-DOWN iPhone. So Apple decides not to trust my iPhone until I can 2FA my way back into it - and then sends a code to that same phone to get me into iCloud...excellent security.
So now...my phone is in security-limbo, and when I try to back out, my only option is to "reset encrypted data," which offers the FAR less than comforting explanation that this will"...reset your end-to-end encrypted data to finish setting up iCloud." What the **** does THAT mean? Considering that it was Apple's in-house video that convinced me there was little downside to signing up for 2FA to begin with, 'resetting my encrypted data' sounds like jumping off a cliff.
30 minutes of Chat-delays, and they've got me going back to my 2FA-advisory email and following a link to turn it OFF.
2FA is apparently NOT READY FOR PRIME TIME. I'd never have signed up for it other than that it's required so as to back up my text messages to iCloud. AAAUUUUUGGGGGGHHHHHH! Stop wasting our lives with these ill-tested security solutions!