I've been banned from the Dinosaur, but I do all the other gas brands.
There's definitely some variation in the criteria between them when it comes to reporting issues, but after doing hundreds it would appear I've developed a good feel for what will be accepted.
If I can see something on the pump (other than checking the tops) from the driver's rear side of the car as I head to put in gas I'll report it. I can recall one report where an editor found a pump dirty that I did not, and a handful with the reverse, but that's been about it.
Occasionally I will hear comments about previous shops, both about nitpicky shoppers and those who may not be quite as thorough as the MSC would like. I use the "above my pay grade" line if they ask about my visit.
Recently, when I revealed, the clerk stated the previous shopper had simply walked into the store with their vest on and waving the LOA, and began the evaluation without the covert purchase portion first.
Have synthesizers, will travel...