I don't agree with your criticisms of metrication. Speed in metres per second equates in numerical terms to about half the value in knots. And it would be a pretty dim pilot who could not add or subtract 300 metres or multiples thereof
Ever tried flying in Russia? At 4am? When you're dog tired?
I can add thousands very well. I can't add multiples of 330m quickly or effectively when I'm half asleep. And lets not even start on the subject of Chinese flight levels at 5:30am.
May I ask, as a Boeing driver do you prefer to work in kilograms or in pounds, which was the unit of weight in which the Boeing was designed?