What OTP settings do you use to log a 3rd-party Android MUA into Google email?

It's interesting how almost all the references gloss over the QR code which most of the OTP Android apps seem to want to use for initial setup.

etc.

Hence I'm still not sure what settings to use for 2FA/2SV/MFA/MSV in the andOTP or freeOTP temporary one-time-password apps on the Android device.

Given there are extremly painful irreversible gotchas involved (e.g., Apple has been sued for NEVER letting you ever turn off 2FV once you turn it on!), it behooves me to line up the 2FA/2SV/MFA/MSV ducks ahead of time.

Especially since I don't even _want_ the inevitable and unrecoverable privacy loss that is a direct result of using 2FA/2SV/MFA/MSV in the first place (e.g., you lose a lot of privacy as you gain a bit of security).

Google references are almost worthless in this regard, as they gloss over the important setup options (as far as I can tell so far from searching).

For example, this Google reference only covers Apple Mail & Outlook but not any of the common 3rd-party Android MUAs such as K9-mail or FairMail. *Set up Gmail with a third-party email client*

Luckily this covers the T-OTP apps, where apparently you get the QR code from Google (AFAICT) when you turn the 2FA/2SV/MFA/MSV on in your account. *How to set up Gmail two-factor authentication (2FA) on your phone*

As does this, but like that above, it's too general for direct use. *What is two-factor authentication and why should you use it?*

In summary, it looks like I'll have to turn 2FA/2SV/MFA/MSV on first before it's clear what the steps are, but bear in mind that if you turn on Apple's

2FA/2SV/MFA/MSV, then you're forever dead as Apple will _never_ allow you to turn it off (which is why I'm being cautious here by asking others).

The problem I have with those apps is you have to have _already_ set up your email account as 2FA/2SV/MSA/MSV in order to get them to do anything:

Flocke free andOTP settings Red Hat freeOTP settings

The problem I have with setting up 2FA/2SV/MSA/MSV is that I've never set it up and yet I'm trying to understand how it works _before_ I set it up.

One "issue" I have (mostly it's a fear) is that I won't be able to access email via Thunderbird/OAUth2 once I set up 2FA/2SV/MSA/MSV since you set it up by account, and not by MUA, right?

So, if I do set up 2FA/2SV/MSA/MSV for my Google mail account, how does that Google mail account know to use OAuth2 for Windows Thunderbird but, oh, say, app passwords for K9 mail?