Is there a reason that most, if not all World Records are done on Linux? I'm looking at the 54:50 and it appears to be because you don't have to re-open the game after the asgore fight in neutral.

That's unrelated to any version, and you do reopen the game, its just a quick openning.

The reason is because of a difference of input handling between windows and linux for 1.001. on windows, while the enter and z (as well as shift and x) are considered different keys with the same action binded, you have to let go of one to press the other, even if its the frame after letting go. Linux versions, as well as Mac versions, dont require you to let go of z to press enter, and vice versa, and the actions are handled with no interference. this makes overflows (for glitched categories), as well as mashing in general much easier to pull off.

If anyone sees that I'm wrong about anything here, feel free to correct, I might've gotten something wrong.