That's my secret, until I know it works or not.
But I will share results once my experiments are complete, either way.
I'd like to have at least a few hundred clock cycles between PWM updates even at the highest RPMs. I run EDFs well above 40k RPM typically.
e.g. a DSP processor would be better than a PIC, at the same clock rates. 16-bits better than 8-bits, etc.