Generally, AutoZone uses a conductance tester such as a
Midtronics, and not like a carbon pile of the olden days. In other words, a LOT like the battery beak. These are very fast, lightweight, and accurate, and do not rely upon the user's skill.
Thhat being said, even a 150A load for 10 seconds will NOT damage an FRC battery. It's not good for this to be done on a regular basis, but 2 or 3 times a year is not harmful.