I am. I'm not convinced that this will allow me to back up passkeys in any way. I wouldn't be surprised if Apple were to allow you to transfer passkeys out in such a way that they don't work on the original device anymore, which would make this standard irrelevant for what we're talking about.

That would be weird to do when they already encourage sync. But if they do, the worst case would be transfer out, back up, transfer in again.