Just get set the regulator on the nitrogen bottle before the race with some trial & error on how many PSI = how many Ft-# on the lug. If you run two guns on the same bottle, the tire guys need to listen for the other guy & coordinate their efforts. You also have to know how long to leave the gun pounding away on the lug, but again, a little pre-race training and you're all set.

I don't know anything about a torque stick, but the impact load from an air gun does make things behave differently than a static torque applied. Try it and let us all know, I am at least curiuos.