Use the dashboard with any postgres role

I have a use case where I will have third parties all sharing one database, and each will have their own postgres role(s) with access to different schemas. I was hoping to let these third parties administer their schemas through the supabase dashboard. It looks like the dashboard is Apache licensed so I could fork it and deploy my own version with this feature, but it would be cool if this was a feature in supabase.com/dashboard.

But then again, these third parties will have supabase auth accounts in this shared database, and if we wanted to use supabase.com/dashboard then we would have to link those accounts to their supabase.com accounts, right? If we fork the dashboard then we can also change it to use our supabase auth login.