I've only encountered it at the San Marcos, TX, supercharger before it was expanded and refurbished and at the Saint Charles, MO, charger. In both cases, they are small chargers, only 5 stalls (although the San Marcos one has since expanded to 12).
At Saint Charles, we really didn't wait. It was full when we arrived, but someone was about to leave. He waived at us and let us know that he was on his way out. No one else was waiting, so we pulled on in.
At San Marcos, no one was actually in a line (as that would block parking lot lanes). Rather, we all just sat in empty parking spaces that were nearby. It was easy to see who was waiting, as that part of the parking lot was empty except for Teslas charging or waiting. Two cars were waiting when I got there. I didn't know which of the two was "first in line," but I knew both were ahead of me. Moments after we got there, someone pulled out, and one of those two moved in. Around five or ten minutes later, someone else left, and the other of those two moved in. Another five or ten minutes later, another stall opened up, and I moved on in.
The whole wait was fifteen minutes or so (we weren't in a hurry, and I was reading, so I wasn't paying great attention to the clock). At least a couple of cars showed up during that time, but no one tried "cutting the line" and moving in on spots. I suppose everyone did the same thing I did, i.e., paid attention to who was waiting when they arrived).
I sure would like to believe that is how it would work in any situation, but I've heard enough stories to know otherwise. Thankfully, the San Marcos charger has expanded to 12 stalls, so