What we ended up doing was populating the Description field of AD with Student - course code like ENG151 etc. This field come thru as Position under User and Location. Since we were not using those fields for anything we put the course descriptions there and can leverage that. It isn't as granular as the exact class but for us, it works.
I create a static user groups based off of a csv of class enrollment obtained from my SIS using a script from @franton's github. The obvious downside is that it is static and doesn't continually sync with your SIS. But, it's better than nothing.
This has been a popular request for some years now. It would be highly useful for K-12 districts that have 1:1 iPad deployments. If we were picking a new MDM today this would be on our must have features list.
