Good day, just want to share my experience,
I am using 2fa as my security in my emails and exchange accounts, so one day I nearly lost my phone and that phone holds majority of my pins, 2fa, etc. so I thought I lost all, luckily I found the phone. So now I'm thinking of buying an extra phone for backup. What else do you recommend for backup?
You should set up the recovery option in your google account. As the 2FA is provided by the Google Authenticator services, you can always keep the backup codes stored over there. This way you can always secure your services and access them by using these universal codes for temporary unlocking. You can ask google to change the devices if you bought new one and I am pretty sure they will make it happen in instant time possible. Thats why there services are best one in the world. They always consider all the possibilities of services that they are providing, so your wont be different and should be resolved.