Im sure someone has found this out in the past but anyways i found a 1 frame faster fpg over normal, i guess if your one frame short in underground you can use it

This is known about, we call it "Agressive Sockfolder" and it saves time using black magic which I will let another member of our community explain how it works.

ah, i figured someone has found it before, i just thought the extra frame came from running speed or something

It's because the game gives you more acceleration when you have "running speed". But this "running speed" isn't directly related to your current speed, but rather it comes from running on the ground with 28 or more speed. When you do the usual Sockfolder FPG setup, you jump off of the stairs with 26 speed, so you never get this "running speed" before you touch the flagpole. But if you land on top of the stairs and then run for a frame, you'll get the "running speed" and that makes you accelerate slightly faster when dismounting the flagpole, saving a couple of frames.

Incidentally, I also noticed this phenomenon back in 2019: But I was told back then that it was already known to TASers well before that.

MHMMMMM