[qlte]

  > Passkeys should be allowed to be synced between devices and stored on password managers in the cloud. I am making my own password manager for my personal use, but have not delved into passkeys.

They are, that’s exactly how I use all my passkeys with Bitwarden. They sync to any device I have Bitwarden installed on when added on one device.

[throwawayffffas]

Yeah that's all hackery I think, if you read at the specs there is always a device involved, bitwarden and company just pretend to be a device or have an extension that just ignores the spec.