Ok found a solution for the latter problem if anyone else has the issue of delayed recording. You have to set up SotBS as a WINDOW capture instead of a game capture. Of course this means you also have to run the game in windowed mode, but I'm unsure how much time if any that costs.

Auth confirmed he's working on a guide, but I can give a quick summation of what I've figured out through trial and error and asking him in chat. Long-story-short the game is really, really bad at actually stopping during pauses, including dialogue boxes.

The any% route is basically:

1. Go around the wall, then hold forward aiming towards the far door until the dialogue appears. Release forward shortly afterwards, and the character should just keep going.

2. Once you're on top of the wall, simply press forward, then press Shield (default L-Alt) and Pause. Done correctly you should see the camera move around the pause menu.

3. Exactly like 2, but longer.

Boss: The game determines damage per button press, not via animation. So every time you mash Fire 1 (default L-Ctrl) you deal damage to the boss. This works through pausing same way floating does. Also the boss' hitbox is really jank (it's actually above the model).

To keep the boss still, simply hold Shield, then jump until your knees clip through him, then pause to stay in place of the hitbox. In phase 2 you don't need to pause because the boss is at ground level (still need to hold shield tho).

That's the quick and dirty of it. A few runs should net an easy sub-4 once you get used to the tank controls and aiming your zips.

I wanted to clarify something. Are we allowed to rebind inputs in the game's configuration menu? And if so does that mean we can bind 2 different buttons to attack for faster boss kill mashing?

EDIT: Unrelated to the above, but is there a way to fully reset the game to the UNITY splash without closing the window? Because OBS really hates detecting the game until after the splash 4/5 times when I load the game from Steam.