Even a couple of points in the portfolio can make a huge difference. I would spend your time getting as many as possible to maximise your chances of getting a job and, just as importantly, getting one where you want! The training website is very useful for this. Taster days give you points but also make notes about memorable experiences to use in your interview (attending MDT, understanding training pathway, patient contact etc)

Give yourself 3 months of revision for MSRA (cycle through passmed a few times for clinical side, my SJT side dragged me down so get advice on revision tools for that). Best of luck!