I'm glad you've had such good experience with autofill consistently working for you. My experience has been closer to that of the sibling comments: 60/40 so I often just give up and copy-paste. I actually did try jettisoning 1Password for Proton Pass but that was even worse, so I went back

> without any migration strategy or import/export support

Since you're already a 1Password user, I wanted to draw your attention to the "Show debugging tools" in the "Settings > Advanced" section. From that point, you can say "Copy Item JSON" and it will give you the details you would want for rescuing the Passkey. Importing it into something else is its own journey that I can't help with

  {
    "overview": {
      "passkey": {
        "credentialId": "...",
        "rpId": "example.com",
        "userHandle": "..."
      },
    ...
    "details": {
      "passkey": {
        "type": "webauthn",
        "createdAt": 175.......,
        "privateKey": "eyJ...",
        "userHandle": "..."
      }