So, if this new strategy/route is the new fastest and will shave around 30 minutes, when can we expect a taste of the new world record run, Death?

I have played this game since I was just a little boy (I'm 24 now), and this is by far my favorite game. I have beaten it probably close to 10 times, every time just being a normal play through, improving on my last one. Ive become a huge fan of speedruns and this website in the past 2-3 years, but I've only lurked, never made a profile, until today. And only for one reason. I happened across this little niche of this website, and I was absolutely blown away that anyone could possibly beat this game in the 11 1/2 hours that is the record. My fastest time was maybe around 35 hours (again, playing normally). Of course, now I had to know what the secrets were! And, wouldn't you know it, there's a few written guides here on how to speedrun it. But I hardly got very far into the first one before I became very stumped. I googled and scrawled the forum posts, but I cannot find an answer. So I was forced to make an account and post here, in hopes that my question will be answered:

TL;DR - What the heck is menu manipulation??

I cannot, for the life of me, find any information on this at all! What is it, and how does it work? I tried watching the video, but that provides no answer, either. And I had figured there would be a little bit on it here in the tips/tricks/skips post, but alas... I really hope someone finds this post and gives me a detailed response, because I'm itching to know :(