The 1password integration works great IME. When a site supports passkeys, 1password seems to offer to save the passkey, and at login time, a little popup appears from 1password asking if I want to use my passkey, and I can either enter my password, or use TouchID to unlock 1password.
I use this across iPhone, MacOS and Windows, and haven't run into any issues.
I use this across iPhone, MacOS and Windows, and haven't run into any issues.