Gradebook limitations?

One of our course instructors was recently asking me why the gradebook was only available for courses with a small number of users.

I discovered that the availability of the gradebook is based on the value of MAX_ENROLLMENT_INSTR_BUTTONS in lms/djangoapps/instructor/settings/ By default, this value is set to 200.

Is there a reasoning behind this value? What are the system repercussions if we set it at 500 or 600? Is there some kind of rule of thumbs with regards to system performance depending on the value of MAX_ENROLLMENT_INSTR_BUTTONS? Has anyone tried it with a larger value then 200? Any comments?

We’re still running Juniper right now without the new gradebook MFE.