The solutions I've heard of usually involve a screenshot of the seed QR code stored in a safe somewhere. Not optimal, but at least gives you a backup in case of disaster.
You can "read" the qr code, extract the TOTP seed and put it into app like bitwarden, where it would be both backed up and can generate the login codes too.
The problem are sites or services, that do use their own variations instead of standard.
The problem are sites or services, that do use their own variations instead of standard.