With brushed ESC's there were no timing adjustments possible. A better ESC could have someting like a current limiter and a frquency setting to help you with a smooth control. Brushless ESC's however can have a wide range of settings of adusting timings to certaing rpm windows and you have to be an engineer to get the best out of it. Not to mention differences between esc's and their limitations by also different firmwares. To bring back racing from enginering they started the zero timing rules which later was turned into a blinky mode to tell tech inspection the ESC is in a zero timing mode.

And this is how to deal with cheaters:
Motor irregularities see Bultynck promoted to European Touring Car Spec Champion - Red RC

I can imagine the use of Aluminium screws was an error by not reading all the rules which is always stupid. But a short made stack is a very serious crime.

people are going cheat. I seen back in the brushed days guys use a tool to crank on the endbell after they removed the brushes..all the laws in the world will never stop a cheater.

I've seen stacks be too short straight from the factory as a manufacturing defect. We can't automatically assume they intentionally cheated, the letter didn't claim it was tampered with. Just that it was missing one layer of laminate.

What I want to know is, why weren't these motors teched before the racing started? Where I race it's standard procedure to measure the stator length and then place a tamper resistant seal on the can before the first qualifier.