The best way to do a switch up(FS) is to come at it switch
You come switch the rotation will do it automaticly since you're already have the rotation set
you pause yourself on the rail and just set yourself when you,re ready by a little pop and set yourself to continue rotating.
it feels totally natural as your upper body won,t have to move as much as if you come.
It`s the same for BS switch up but then it`s to go normal stance