I went back to look over an old post concerning this problem and found these pictures for reference, FWIW.
The front to back photo shows where the arms/pads of the lift were placed by this shop.
In this photo the front two slots, where the pucks are suppose to go, none were used in this for the 4 post lift.
The pads on the front two arms are placed in the noted jack stand locations, per GM.
In the rear, again no pucks that I can see here, however the pads to the back two arms are not... on the suggested jack stand points per GM.
They do look like they are placed in the extra welded square area, with one of the pads,
on the frame rail and in contact with the rear panel on the car.
In this second photo, looking from the rear of the car when lifted it looks like a pad is added to the lift arm, but again here
notice where the lift pads are placed. Not on the rear jacking points for our cars. On the front two arms with a puck attachment
these are placed on the front two jack stand locations per GM.
Combine these two photos and you have a clear picture during your next visit to the dealer or any shop when lifting your car.
Talk to the SM or Fast Eddie the tech wizard, show them these two photos and what's wrong with each of them before lifting your car.
Does this add confusion for us as owners? Hell yeah it does, but the opposite of where or how they place the lifting arms/pucks when you take your car in for service IS... broken, cracked panels on ours cars. $$$.
Pre-work walk around/look over before any work is done.
IF the shop in question does not follow your instructions as to where or how to lift your car... take your business elsewhere imo.