There seems to be a bit of an issue with how Rahituber recognizes mouse movements. Particularly, changing programs that have different FPS (in the example in the video, going between the Fortnite lobby and in-game resulted in some weird jittery motions, especially in layers that have inherited motion. I don't know if the FPS different is actually the cause or not, but that situation where there is a program i have focused is changing between two states of a limited FPS and a free FPS seem to cause it. You can find an example in the video below! The clip about it starts about 1:35
I think the mouse movement being jumpy is a result of the game grabbing your mouse and forcing it to move to the center of the screen (or some other similar thing, games all do different stuff with the mouse and it's hard to account for).
RahiTuber directly translates your mouse's position on the screen into a position co-ordinate for the layer, so if the layer jitters, that means the mouse jitters. I'll try to add something to smooth any sudden jumps.