2 factor authentication (new version)

[Skoal]

Has anyone running iOS 9 or 10.11 beta for dev's tried the new 2 factor authentication? If so were you running the previous 2 step verification and what did you do to transition?

 

[rnbwd]

i'm also curious - is it 'random selection'? Is it only in public betas? And how do we know!!??