Figured I’d toss this in this forum here.
It would be nice to be able to use a FIDO2 security key in lieu of the mobile authenticator app.
In addition, adding sign-in with Microsoft Accounts would be extremely useful as that would allow me to use my Windows Hello sign-in to log into battle.net applications and services, unifying the sign-in functionality of my PC (and reducing the amount of authentication codes, etc that I need).
Although I’m not sure, it would be useful to tie the authenticator to the security chip on the phones as well via a private key + nonce setup for mobile authentication. In this way, an attacker would have more difficulty phishing a user for an authentication as the attacker would require the physical phone device in order to digitally sign the nonce.