Ability to see all read-only collaborators in a report

Current, if we have base read-only collaborators, the only way to view this list would be on the individual base. There is not a way to view an entire list of all read-only collaborators within the workspace. The workspace list will only show you the billable collaborators. However if you have lots of bases (what Airtable would want presumably) there is no way to view a report of who can view your bases. This is a potential security issue. For example, we had an employee leave, but they remained a read-only collaborator. Since we have no easy way to review all our bases, they remained on a base that was missed. It’s an administrative burden to go search each base. Please add some kind of additional reporting on this.