It enables reting scaling functionality on any external monitor, regardless of the resolution or the Apple compatibility.
It's great for 2k monitors that are totally hiDPI but are not deemed enough by Apple, and even for FHD secondarh displays that don't need that much display real state so you can use that real state to scale everything nicely.
Also nice is BetterMouse [1] (unrelated author). It's similar to the OP application in some ways. And it uniquely has a way to flip between spaces on MacOS that has very low delay, without breaking SIP. No idea how they did that.
Lol the way it seems to do this is by simulating swiping on the trackpad really hard. I.e. create a synthetic CGEvent with the undocumented but well-known fields set to treat it as a fluid swipe event, then just put a large number in the swipe amount.
See e.g. https://github.com/thenickdude/wacom-driver-fix/blob/bdfda9a... for context.
Is this better?