So, without debating the merit of SIDs, but instead CASA's decision making.
Why has Australia mandated something that the country in which the aircraft is manufactured and the country that set the design standards that are adopted by the rest of the world is not making mandatory?
Is this another ADS-B type example where Australia is on its own ahead of the rest of the world, with no reasoned logic and not looking over its shoulder to see if anyone is following?
What is the logic, or where is the evidence that Australia should make it mandatory for all Cessna aircraft in all classes of operation when America (and I'm assuming all other countries with significant GA) are not?
Why is CASA's decision making not transparent? How can decisions be made that cost s significant amounts of money be made without the decision logic ever being prosecuted?