roles v roles

There are "roles" in the KMC when adding a new user.

There are "roles" in the config.ini.php.

I'm being asked to customize the "roles" in the config.ini.php to change the behaviour of the demo app, without actually changing any source code.

I'm failing to see the connection, if any, between KMC roles and config.ini.php roles.

In addition, I'm failing to see a clear path from config.ini.php to any kind of meaningful change at all.

In particular, I believe they want a role somewhat in between PrivateUpload and KMC Admin that can view all the private uploads, restricted perhaps by category or other features.

The Big Picture is students submitting work, not visible to other students, and gradable by instructors, with a clean and clear separate of each course and section from the other.