Holeshot device + air fork & traction control

Hello everyone,

I recently bought a low ridden 15' 450 Kxf.
Bike is awesome and I feel very confortable with the air fork despite my early concerns.

Next sunday is my first race since 2015 (got a child) and except a few try at the track last week, I have not really worked on starts since the new bike.

My riding buddy told me to invest in a holeshot device since it will make my life easier to deal with the power of the 450.
I have no time left to test it before the race so here are the questions :

How high should I install it on the fork guard ? Does air fork makes it different than spring fork ?
Should I use it with the traction control activated ? 2nd gear ?

Here is the device I bought :



Track is typically french : harded packed slippy clay and rocks.

Thanks a lot,
Have a nice day.