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Authy got hacked, and 33 million user phone numbers were stolen
(appleinsider.com)
This is a most excellent place for technology news and articles.
Use aegis, export the keys and then reimport them every time you switch. Trusting your second factor to a cloud is a disaster waiting to happen.
If you want to get fancy setup your own cloud server (nextcloud, Seafile, owncloud etc) and set the backup folder for aegis to the self hosted cloud for easy restore every time you switch ROMs.
Simpler approach: auto export from aegis when an update occurs, syncthing or similar to your home PC. I have it synced across several computer in different locations and aegis is good enough to make unique filenames, combine with syncthing file history and I'm good for like 2 years of backups.