Seedvault (AFAIK with my profile) won't perfectly back up stuff like authenticator apps, and this is the last thing I've yet to transition from my last phone.
I'm on my 3rd reset due to a sim change (with GPS I can turn it off, but it didn't like setting up twice now) so I can use the physical for international roaming, and I'd rather not lose access to all my authenticators completely if I'm required to reset again.
What would be the best way to keep a private key private but backed up, I can transfer between phones and keep OTPs, but there's seemingly no way to back up all these keys without being a massive hole in security. I'm thinking about buying a mooltipass key manager or a YubiKey and to move to physical devices instead for Oauth/OTP stuff, but if I could back something up into seedvault with its long password chain and only have it reactivatable on the same device at a hardware level I'd rather do that.
The pixel has its own hardware to host an esim, why wouldn't it be possible to make a hardware-backed key to restore auth on a software wipe? If there are other alternatives for those OTP managers that are their own devices or software I can restore, but only on a specific phone with a password, I'd be interested in finding out how to set that up.