So basically what title says.
Im using 2FA with google authenticator for multiple accounts. What if my phone gets stolen? Can I have some kind of backup? Or maybe sync with some self hosted service?
Bonus question: what 2FA should I use instead of google?
When enrolling with the 2FA take a screenshot of the QR code, print it and add it to wherever you keep your secure documents. The QR code is your private key, just scan it again to add a new device if you lose your original.
Obviously you need to keep the code secure!
FWIW if you use Aegis, that app will show you the QR codes after the fact.