Allow disabling SMS two factor
Cos
If you have TOTP (authenticator) MFA enabled with SMS as a backup method, you should be able to disable the SMS backup easily, WITHOUT resetting your TOTP key. The need to re-register with all your authenticators is a strong disincentive to disabling SMS, and SMS as a backup these days is a vulnerability. You need to encourage people to remove this vulnerability, not actively discourage them by making it hard.