Optional username

Is there a way to make username optional.
In case where administrator creating users and sending invite links as suggested here, it’s obvious admin cannot decide on the username. But when users use signup, user is in control to create username. So when Username required setting is enabled for the users to set the username, same setting is preventing admins to create user and send invitations.

How is this valid? or am I missing something?

There is no optional username feature at this time. The admin will have to create a username for the user if you want to use a connection with a username. You could use the user’s email as a placeholder username.

It is possible to have the user update this on the first login using a redirect action. If you take this approach, you will need to write the logic and create a UI for the redirect page that updates the users username.