So, I started playing rotationally shortly before getting DU and just continued playing and learned a lot.
I have continued to switch households between 12 and 6 am on Sundays and I even have my families labeled so that I rotate through them in order. This means that my sims at the university have waited 5 or 6 weeks for me to return to them. I have put about 3 sims through university in this way.
By the time I leave them, they just need to take the final exams on Monday, but I have completed all other course work. All of them have grades of a B or higher. They stay in the dorms until I come back to them and I either get the prompt to re-enroll immediately or to move them out. I have had one sim finish two terms and them enrolled another sim and moved them into the same dorm. When I played, I got the prompt to enroll them both and continued as usual.
Playing this way, however, means I don't see their grades for each class, just an overall grade. And I miss their graduation. Which is fine, I mostly send them to Uni for the storyline and career boost anyway. But from what I am reading switching to a 6pm Friday rotation would correct that for me?
My biggest annoyance is that my sims usually find a spouse while attending university and while those NPCs show as graduated, they do not have the trait. I have had to use Carl's cheat guide to correct that, in the future, I'll try adding them to the household so that both spouses have the skills and traits that come from attending university.
Anyway, hope I added something helpful to the convo!