Looks like a huge amount of security vendors are working to have a secure and open standard for passkey portability between platforms.
It is always good to see major collaboration in the security space like this considering the harsh opinions that users of some of these vendors have toward many of the others. I just wish apps and sites would stop making me login with username and password if passkeys are meant to replace that lol.
I have my passkeys in my keepass file in my private cloud since about 6month using strongbox on iOS and KeepassXC on Linux. Sadly, not many websites support passkeys on firefox for linux desktop yet… Hope this helps!