Picture Attached :: Why is the reset button there in the first place and what does it do?

not sure what you mean by “not work” but the all the “reset” does is center the mouse cursor after the movement has been done.

its just an option, may be someday you will need it maybe not. a use could be having a different part of code manage the cursor. maybe its to have multiple mouse move acts work better by only centering once rather each time.