The game currently uses software mouse (January, 2021). Software mouse makes the mouse cursor slowly lag behind/animate towards your intended destination. Hardware mouse, on the other hand, instantly teleports your cursor to where you want it, like in Windows.
Using software mouse feels really bad for some people like me, so an option to toggle it off would greatly improve the game, in my opinion. In other games this option is typically a tickbox called things like "raw input" or "hardware mouse".
This would probably solve most complaints about "mouse lag".