All of that just locks you into Apple’s platform and now I have a problem copying that passkey to chrome.
However, a sibling commenter mentioned QR code export/import. That would alleviate the concern and be even more elegant, especially if it automatically created a new passkey registration instead of just copying it around.
AFAIK QR code export is not a thing, just speculation for how passkey exports could work (which I doubt since QR codes get hard to scan the more data you pack into them; maybe you could ask the user to hold the camera to the screen for a minute while the target machine cycles through each passkey, or cycles through qr code data itself to facilitate error correction and 100% data transfers)
That commenter is mistaken. The QR code is for authenticating on your computer via your phone over Bluetooth. It does not export the token to be used by another authenticator, you have to have the device with the Passkey anytime you use this QR code method.
However, a sibling commenter mentioned QR code export/import. That would alleviate the concern and be even more elegant, especially if it automatically created a new passkey registration instead of just copying it around.