I don't work at a mechanics shop. Costco prior to probably 15 years ago used to just throw wheels on and hit them with air guns without a torque wrench in sigh

I don't work at a mechanics shop. Costco prior to probably 15 years ago used to just throw wheels on and hit them with air guns without a torque wrench in sight. Mechanics shops snapping wheel studs was a common problem for years. A decent mechanic would know to never use a high torque impact gun on something with decently low torque threshold, as I said in my OP about experience. But that shows you how many years and millions of cars were/are on the road without caring about exact torque. The reason Costco does this, and does it twice, is to make sure the lig nuts at tight on the first place... So you don't leave with one loose. The fact that they use a torque wrench is just because they got tired of replacing wheels studs.