Personally, section 1 actually requires the most concentration. But yeah, some section 3 qs are just unreasonable... until you read the worked solutions that is.
I guess we just gotta find solace in the fact that it's the ranking that counts, and that 70% or so (idk actual stat) are of the opinion you can't prepare for Umat and subsequently die in the actual one (figuratively of course).
Would definitely agree section 1 requires most concentration, although there are ways to make it easier (e.g. display info given in a table). Honestly the best feeling is when you see a section 3 questions, and you recognise the pattern from a simple plot, or when you figure out what's going on (which idk if you guys bought section 0, but god damn it makes things easier aha)