The torque stick set I had (was for cars) came with instructions for calibrating the impact wrench. I don't know if this applies to the one Jack has.
The short version ;
Tighten a nut (with a known good torque wrench) to the value of the torque stick.
starting with low air pressure on the impact wrench, start tightening nut as you increase air pressure.
When the nut turns, back off the pressure slightly.
Install another nut with the torque stick.
Verify the torque with a known good torque wrench.
You have calibrated your impact wrench & it will use the same air setting for all sticks in the set.
Torque sticks are a torsion spring and you can exceed the rating if you drive them hard enough.
My local tire store uses torque sticks. I watched & verified the one used on my car was 80 ft-lbs. When I got home, I tried to remove a wheel to change brake pads. It took about 300 foot-lbs (my 200# standing on a 18" breaker bar & I bent the bar). I went back to the tire store & found no regulators & a 175 psi air compressor.
I take my own torque wrench now, it is so much easier than replacing wheel studs, nuts & etc. & then trying to collect restitution.
The plastic & duct tape are great ideas!