I've tried for several students and the grades remained the same. I do it a bit different than starcrunch though.
I just enroll the current household Sim(s) on Friday evening as soon as I start to play with the household. They then actively do their term which starts on Monday. Shortly before it finishes (4.59 pm), I save.
I then stay for another hour (6 p.m.) to see their grades, but do not save again. Instead I go to manage worlds without saving (--- This step can of course be skipped if you're not too curious to see the grades ---)
and then rotate to the next household. When I come back in the next rotation, the Sim can just start the next term, nothing is lost, they don't have to leave their dorm (if they live in one) and keep their scholarship.
That way, I play all my university Sims actively and control their grades.