I seen that playing in windowed mode can help in Act 1 with reaching the ball to die, but how do I play in windowed? 

I know this is from 2 months ago but i have several things id like to mention:

1. There are multiple setups you neglected to mention, including the most beginner friendly one. The one you did is known as sad sgs, and only a couple runners actually do it that way since its hard to just wing it like that, although its not that much different from a regular pce. the most beginner friendly setup is to move up 2 pixels, and when the cutscene finishes, move all the way down. the trigger for the next cutscene isnt actually dependant on a physical trigger, its because the thing triggers after moving 6 pixels in any direction. So moving down with this set up moves you 5 pixels. For the final pixel, youd wanna hit right, c, and enter at the same time, and then z any time after, which is alot easier to prepare and react to than sad sgs. Theres also slightly alternate versions of this strat and the one you showed, where instead of menuing down the cell phone, you use the stick, since you always need to get the tough glove regardless of category (with only low% as the exception). This is tighter as you need to hit an action key 3 times instead of twice, which means pressing enter again after your z press. So no matter what set up, its c and enter to open the menu, z to confirm the stick, and then enter again to use it.

2. This is not genocide only. All glitched categories do this glitch in the exact same setup, and the timesave is the same in every category in the game except glitchless. Not doing it loses 30 seconds in all categories. The only categorical difference is that papyrus will talk in the first cutscene before the actual trick, but that doesnt change the setup at all.

3. One thing that i'm kind of confused that you didn't mention is that there is a visual cue for the setup.  On the left of the screen there are those gems, and when they get cutoff at a certain point, then thats where you should have moved to, and pressed the menu button. Dont take my word for this exactly, i just know that there is a visual cue, its in the guide

4. speaking of which, there is a guide. a few guides actually, not just one. Ocean has his original video from when he found it before most people made discoveries about it, shayy has a twitch clip of his setup, the beginner friendly setup i mentioned, there are the many runs that do sgs that can serve as what it looks like to perform in runs, and shayys most recent neutral video guide from late last year shows him performing and iirc explaining sgs as well.

edit: theres also the general text guide that all runners should read up on that explains sgs in the genocide guide, as well as in the neutral/tpe guide.

It's a neat video guide that i thing could be great if you were just a bit more specific, and its always nice to have these kinds of guides, and this was 2 whole months ago and i only just now saw it, but these are my opinions on the video and my thoughts when i saw it

have a good day nxnjaa!

Can someone tell me what the most important commands in console are for speedrunning? I have the basic ones but wanna know if there's other ones that are helpful for runs. Thanks :)