@greg-wizards If you enable two factors authentication in any service, you will get a backup code (or a few of them) to be used if you lost access to your authenticator app and/or to your device/phone number. Opera gives you a backup code too.
And although some sites allow you to have more than one method to get your authentication code, many of them only permit that one method is used at a time.
Opera is not blocking any address, it's a matter that can't be two accounts using the same email address at the same time.
I don't now if Opera cancels the account after a period of inactivity but if it does, that period most probably is long.
