At the moment, yes, that's the process, annoyingly. Ideally, you would sign up with one and then be able to automatically enroll the others, which is in princip

At the moment, yes, that's the process, annoyingly. Ideally, you would sign up with one and then be able to automatically enroll the others, which is in principle possible if you don't use resident keys and instead each device has the public key of the other devices you want enrolled at the same time, but I don't think is currently supported by the standards.