What is apparently the official Firefox policy is incredibly '''dumb''': They provide users with that ability to add secondary email addresses, recovery codes, and authentification, '''BUT ''' they REQUIRE access to the primary email address to make the secondary email address primary. '''IF '''the primary email address is unavailable, the secondary email addresses, recovery codes, and authentification are '''completely useless''' for making the secondary email address the primary one. This supposedly provides "enhanced security". '''Pro Tip''': If you deny ALL internet access, you will be very secure on the internet. '''Not''' very useful, but.. Genuinely astonished that Firefox Support thinks this is not insane.