Our existing system restricts users to single organization affiliations, overlooking the possibility of users ebing members of multiple orgs at the same time. To address this, the proposed solution is to establish a many-to-many join table between users and organizations.

Update: Let's just move the organisation_id from users to students table instead. This would mean that individuals are restricted to one student profile per course per org, but that seems like an acceptable restriction, and it would also mean that org admins can view progress of only the courses that concern them of a particular individual.