1. currently, we are using a stick's channel to send mouse data to SWITCH, but the MAX speed of a stick is limited.(MAX=5, for Splatoon 2 )
when you swipe too fast, your mouse will reach the limitation very soon, and the hold time is much lesser than slow movement.
so you will get a smaller turning when you do that.
we suggest you should adjust your mouse skills a bit, and use a gentle way to move your mouse.
and we are releasing a new version for SWITCH, you can try it later. it has a new curve embedded.
2. have you tried to use a stick to do a diagonal movement? you can do a comparison.
diagonal movement will not be as smooth as we hope, if we use a stick for control.
this game is designed like this.