Cast your minds back prior to JAR introduction in 1999.
At BAe flying college Prestwick, the course included five flying progress tests in the single engine phase.
The final test was on the AS202 ~ Bravo, a fantastic Swiss aerobatic trainer.
As part of the G/H test, the five basic aerobatic manoeuvres had to be demonstrated.
So the basic skills were learnt by junior birdmen during basic training. Mainly BA, Cathay and Gulf Air students from 1988 under CAP509 approval.
Compare that to what EASA requires now for licence issue............and what is proposed........
You need to teach it prior to licence issue to an appropriate standard. Sticking plasters don't work.