Rereading/rewriting notes isn't very worthwhile cuz creating flashcards from notes already solidifies it in a much more productive way with the spaced repetition mechanism. I don't recommend flashcards for calculation questions, they're better for memorising pedantic stock responses expected from you by VCAA. Don't push yourself with those quiz scores cuz they don't contribute to your SAC marks, just try to understand the concepts covered regardless of your results in them. One study strategy I used a lot in biomed + uni chem units is to teach the concepts I'm learning to my peers, either in group chats or on the unit forum. The ultimate goal is to explain this concept to a twelvie such that they understand it. If you can do this, you can certainly explain to the assessor that you know your sh*t on your actual SAC/exam. You can also try writing your own exam-styled questions after you have attempted a few past exams to reverse engineer how the marking scheme works
I failed the UMAT in my days with a 57th percentile so I doubt I'd be much help with the UCAT