On the topic of the holeshot device I've found there is a way to compress both the forks and the shock on the starting line, however you can only compress them by a small amount. It isn't the most refined technique in the world and to be honest I think it makes absolutely no difference what so ever but from what I've seen in this thread it seems like it's the closest thing to a holeshot device that you're going to get.
.Firstly I suggest turning on /togglegraph to watch your suspension data while practising this.
.Sticky Sit Dab will also have to be turned on.
.(This is where it starts to turn crap) While sitting at the gate reverse a little, then gas it it and swing off the front brake lever.
. If you only want to compress the forks that's it, as long as Sticky Sit Dab is on.
The way it works is after you reverse then go forward and brake it compresses the forks, but Sticky Sit Dab will apply both brakes once you've stopped. As the forks compress the wheel base gets slightly shorter, so when you let off the front brake to use the clutch Sticky Sit Dab will hold the brakes while the wheelbase has been shortened slightly therefore locking the forks down to wherever they compressed to.
To get the rear shock to compress is a bit tricky and often doesn't work all that well.
.Hold in the rear brake
.Get on the gas for a second
Sounds simple but often doesn't work well, hopefully once you've let go of the throttle the wheelbase will be shortened even more and Sticky Sit Dab will hold the forks and the shock down.
On the off topic, topic of the tear off ban, screw roll offs they don't work and I've heard a few pros whinging about it now, and I hate cows so much for the -4 IQ that they have.
Anyway I hope that helped you, and if it didn't then I wasted my time.