When you first start out autocrossing, I'd suggest that you leave it on and let if 'help' you learn to drive. Very soon, it will start getting in the way of faster times and you will feel it taking power when you want power. Then it is time to turn it off.
Make that part of your starting grid check list:
ASR off,
A/C off,
Cinch the seat belts,
1/2 tank or better of fuel - "before you get to the track check list"
Add others as you need to.