It's disruptive as hell. You end up sitting on the line waiting for the instructor to diagnose some turd carbine.
While running team drills, downed vehicle, the shooter I was paired up w/ kept having problems. Their carbine went single shot. Hundreds of dollars and a 6 hour drive later I felt slighted out of valuable training.
I had a lady schedule a private instruction. She showed up w/ a High Point. the majority of the PI was spent messing w/ the low quality handgun.
The creator of the chart, IMO, was a great source of straight forward no nonsense honest information. The kind I prefer as the candy coated BS is a waste of time. He spoke his mind. Many don't like honesty when it doesnt support their assumptions. He once sent a jab my way. At first I was pissed but then after a minute of thought I realized he was correct.
From my understanding the author of the chart is locating and deleting all traces of that document. It is a shame as it helped create informed consumers.