After the level 4 glitch in Any%, I've seen many players pause the game after going into each pipe. I can't find a guide on how to do so. Do you manually pause, or is it automated?

You press tab to cycle the options. Like Menu, Panic, Pause etc. Press tab until you get to pause once there leave it there and when you press space bar it will pause the game.

Thank you!

Enough people have asked this that there should probably be a guide made.

There is a guide. Check under "Guides".