I've some quizzes with manual grading questions and this plugin seemed an useful one. Unfortunately it has 2 drawbacks:
1) Filtering by group doesn't work
2) Students are identified by ID, not by name, which worsen problem #1, as I end up having more than 200 students identified only by a number. Is this intended?
I'm reporting this bug here because I don't have a GitHub account to report there directly. Maybe I'll create one later, but reporting here may perhaps be useful for other potential users of this plugin.