I play on a 1440p monitor, and so I usually play in fullscreen, but this caused some problems with my display capture blacking out for a moment when I switch to windowed to open another client (judgement hall/photoshop flowey sort of thing). I found a piece of software called Sizer.

I checked the rules, and since it doesn't read anything from the screen or game memory nor does it control the game with macros, it should be OK, but I want to be completely sure.

TL;DR: Would I be able to submit a run where the window is a different size than the game allows because of external software?

I found undertale KPS in the resources tab but I have no idea what it is or how to use it. could somebody please help me, I'm using 1.001 linux. (noob question ik)