At one time in the 70s, the fast jet crossover mill was populated by a bunch of QFIs who seemed hell-bent on making heavy guys lives a misery - the chop rate was more about guys who had had enough psychologically than their ability to fly. A friend of mine got a FJ crossover slot, but after 3 months of torture voluntarily withdrew from training and went back to heavies.
The stories he told [allowing for self pity, etc] were horrendous. Tales of derision, bullying and pressure, rather than teaching.
It seemed at the time as though you had to be the self-made Top Gun to stand any chance. There was no room for the guy who needed another few hours to make it all click and come together.