You are welcome, thank you for the feedback.
Let me give you some context so you understand the rationale behind my answer.
1. Listing the OrgUnit would need G Suite admin permission, so teachers who are regular G Suite users won't be able to get this information.
2. Listing OrgUnit is part of Directory API, which means I would have to go via Google's review and approval process for these additional OAuth scope/s.
I can consider adding one more sheet tab (like add students one in current version) for Admins only to list students with OU, but I need to understand if it is worth the effort.
If you can write to me in details on requirement via my website, that would be helpful, or if more Admins request this same feature here.
Workaround for now -:
1. I have another add-on in G Suite marketplace called "Ok Goldy" which can help you export all your users along with their OrgUnit details.
2. You can use Classright to get students' email ids, and Ok Goldy to export all users (both can be run in one single Google sheet together), and then a vlookup to put OU in front to students.
Hope it helps.