Not really, I just would like to be able for anyone to become a contributor (ie write post) without having me sending him an email.
For example I can have a page where the user answers a form with his email and ghost automatically invites him as a staff member with the contributor rights.
Did you read the topic about how that is a bad idea because it opens you up to potential security issues? You’re better off building an alternative method for public to submit articles to you than letting anyone in as a trusted admin user.