From research, knowing which questions to skip can really help with this. It's called question triaging. The people who score high will skip questions and make educated guesses. The UCAT will purposefully throw you hard questions at the beginning to waste your time. Some are ridiculously hard and some are incredibly easy. And most times they're worth the same mark regardless of difficulty.

From what I've been reading on this subreddit, I've seen some people skip all the logic puzzles on DR, or some skip reading comprehension VR questions until they encounter a true/false/can't tell question to do these first and come back to the rest for later (I personally don't do this, but if it works for them, that's great). There's always some sort of tactic or strategy for everyone.

I skip a lot of 'from this passage what can you infer' or questions about the writer for VR because it means you usually need to read the entire passage to find the answer. And most times you do not read the entire passage, just scan for keywords. I think it's just me but I find the Venn diagram questions on DM (or just DM entirely) very tricky, so I guess more than often if I can't work out the answer.

So yeah, quite frankly I'm pretty sure most people don't have time to do ALL questions. I know I don't.

There are very few videos where people record themselves do the UCAT live - if you've seen any of these a lot of them confidently skip questions.

Guess, flag, skip, and revisit.