These are the pros I see for the Passkeys:

      Most of our users will start by having just one Community

        That makes Passkeys a good option.

        Contacts can make Passkeys multi-community

          If the user wants to move further with Seed Identity System, then the user downloads the app create a Contact a adds all the passkeys Proofs.

      Passkeys do NOT make the hypermedia server a custodian

      Passkeys can execute other action than login other sign up

    These are the Cons a see:

      Your Account Identity cannot be shared to the SHM App

        It is stuck in the web

      Your Account Identity cannot be used on multiple sites

        Although maybe you can redirect to the site which has your identity? But this might have a very confusing UX