The impact drivers we are speaking if will do what an air impact won't.
Its a special hand held tool that you smack with a hammer and it slightly rotates whatever tool tip you put in it.
The reason they work so well in this application is that the hammer blow provides the force to hold it down in the screw slots at the exact moment its needed, when its trying to jump out and slip.
Best way to use them is put downward force on them by hand, rotate slightly in the direction you want to go, which "pre loads it" and then smack it with a hammer.
You want your carb body laying on something soft but sturdy, I usually just pinch it between my legs while sitting down. I get bruises but no broken parts. Some of the screw tabs stick out from the body and potentially could break off if you don't finesse this.
The tool has a setting on it to make it go either CW or CCW when you smack it.
They are also invaluable for getting the rotor screws out since those are equally shitty metal that strips the head out easily.
They're a marvelous tool.