In early with my guess. First, I assume you mean the socket extensions that are color coded, and flex at a predetermined torque?

I would imagine that they flex when they flex. So, if the electric impact generates the same tq as an air gun, the result will be the same. I've always *guessed* that using them resulted in approximately X tq, or Y tq, (or whatever tq)as long as you didn't spend an hour on them with a 350ft lb gun.

This is all a guess though, and I will be interested in learning more.

One fear I'd have is that if using an electric unit, and the battery is not up to snuff, you could have an undertorqued nut.