>if I enroll on iPhone, is my identity forever tied to Apple or can it be migrated to Android if I ever wanted to change platforms? A good FIDO implementation

>if I enroll on iPhone, is my identity forever tied to Apple or can it be migrated to Android if I ever wanted to change platforms? A good FIDO implementation will give you the ability to enroll multiple authenticators. In fact, if you can't, you're basically going against the WebAuthn spec. "Relying Parties SHOULD allow and encourage users to register multiple credentials to the same account. Relying Parties SHOULD make use of the excludeCredentials and user.id options to ensure that these different credentials are bound to different authenticators." Basically, you should enroll your iPhone and a backup key. And if you get an Android device, you log in with the Android device using a backup key, and enroll the Android device and remove the iPhone. Alternatively, you remove the iPhone authentication using the iPhone, and enroll the Android device using an alternative authentication method (like traditional username/password).