I'd say, Go for it! Change it to 1000 grit since you have low revs and aiming for erlier roll. Dont forget to sand it against the track, not along the track. Im sure there are other ways of using the ball without changing the grit, stuffs like lowering speed, lowering your axis rotation and lowering your tilt if you know what I mean. However, life is full of trial and error, you wont know unless you experience it.