Don't discount the bump from understanding the pacing and difficulty of the exam. You might have 25 questions in 30 minutes for a math section. Understanding that which sections are easy and which are hard allows a student who has seen the exam before to allocate their time more efficiently.
Sure. And even taking the test once under real live conditions is probably beneficial to complement a bit of study. Just as really giving a presentation to even a few people almost certainly beats just mentally walking through it in your head.
Obviously you can try to create a real simulation but it's probably not the same thing.
