Psyxwar, articulate and accurate as always

From my experience (97, 61/60/72) the most important part of my preparation was definitely time management. Usually when people ask me about my preparation,
time management and getting back to basics with your exam technique is the main point I would stress. I believe that it's
difficult (not
impossible) to improve S1 and S2, and maybe show a bit of improvement on S3 of the exam. They pretty much design the UMAT that way in a sense. They aren't testing any prior knowledge, just critical thinking and logical skills. That being said, it would be foolish not to do at least some practice; in S3, with a bit of practice, you'll be able to recognise a few recurring patterns that come up again and again (e.g. angle movement 45/90/135/180 etc)
So if that's something you can't improve, you could at least give yourself a better chance of using the skills you do have to have a really good crack at all the questions. This is where planning out how you're going to tackle a 3-hour exam comes into play. Finishing the exam with enough time to have a read and educated guess (at the very least) of each question will be very advantageous, compared to those who have to play catch-up and wildly guess the last 20 or so in the last 5 minutes of the exam.
I personally also did the UMAT in different sections; S3 first, since they were easy to spot and I found S3 to be one of my stronger sections - then S1, because they were clumped into sets related to one passage (usually) and I wanted to make sure I got them done - and then S2. I finished the exam with 15 minutes to spare after making a conscious effort on every single question; then I just went over and made sure the right bubbles were coloured for the right questions, I wasn't missing any, etc.
To end, I did do the MedEntry program, and mostly relied on their online portal for practice exams. Truth is, you could probably find these somewhere if you looked hard enough so in a way, this renders the portal (and the program) not worth it? I did around 5-6 full length practice exams in the lead up to the UMAT (also starting a month-3 weeks ish before, you still have school SACs etc) and experimented with my exam technique, straight through from 1-~134, or by section 1/2/3. Don't be too disheartened by scores you get on that portal though; I was scoring 80-90/134 on all my trials.
Also - agree that some of MedEntry's S3 examples are out of this world insane - the reasoning they give when you go through the answers...
*facepalm*