I make notes and bullet points and hopefully cover them while remembering the actual content for each point etc.
For me, the most challenging VI questions I've had were actually when they were softballs rather than curveballs, which I wasn't expecting, thereby becoming curveballs in themselves instead. Also why I said I think I botched my Weil VI cos with hindsight I feel that I didn't do the first question (which is 2-parter on motivations) very well cos I expected a much more challenging and impersonal question
I think the worst part is sometimes being told that they don't want rehearsed/memorised answers but sometimes you do so many VIs that you essentially end up memorising answers and looking "robotic". Totally agree on your point about human interaction being much easier than staring down a timer too