It’s a great option, but it’s debatable whether or not it’s privacy improving. On one hand it’s your domain. You don’t need to worry about moving email services, and as you control it, you can have as many addresses as you want. One for each service, catch all, and so on. On the other hand it’s YOUR domain. Only you have access to it. It’s quite easy to filter out the first part, before the @ sign, and identify exactly who you are. It’s a unique data point, tied to you. It’s arguably as bad as handing out a phone number.
Depending on your threat model, consider printing them out. You’ll have a physical copy of your keys, not tied to any electrical good. Even if they get stolen, they’re not usable, due to them not knowing your password.
Alternatively keep a digital pdf, or txt document with them inisdie. Save that document on a a USB drive or SD card. You could save it on your phone, but it’s best to keep your backup codes away from your normal 2FA codes.
It’s a great option, but it’s debatable whether or not it’s privacy improving. On one hand it’s your domain. You don’t need to worry about moving email services, and as you control it, you can have as many addresses as you want. One for each service, catch all, and so on. On the other hand it’s YOUR domain. Only you have access to it. It’s quite easy to filter out the first part, before the @ sign, and identify exactly who you are. It’s a unique data point, tied to you. It’s arguably as bad as handing out a phone number.