I’m wondering, though, about scalability. How many “unofficial” students were in your course the last time you taught it? How much did taking care of them add to your workload? How many more students could you handle before you said “uncle”? One possibility for scaling this model further would be to find additional faculty members at other institutions (perhaps those who have agreed to respect your grade and grant local credit) to partner with you to grade / mentor students from their institutions. Not sure exactly how the logistics of this would work, but scalability seems to be the next big iteration . . .