Triadic. Really good rational post.
Of course one of the problems is that the casa officers who introduced the change ( or clarification as they called it ) probably have very little knowledge of how the North American airspace system works in practice. I understand most of them are ex Australian military with quite fixed views on how our system should operate.
And it’s also obvious that some others on this thread have a similar lack of knowledge.
One of the first things we did before deciding on the AMATS changes was to send a group of ATCs , pilots and CAA regulators to the USA and Canada to actually fly in the system. From my memory all involved where impressed with various parts of the system.
That’s what CASA needs to do again. The CASA officers who are pushing for the giant unique 40 mile CTAFS need to go to both the US and Canada and see how the system works so well there without such huge CTAFs and prescriptive regulation. They need to discuss with their regulatory colleagues in these countries how they operate with a far simpler and more ICAO compliant system.
Then they need to have open minds and decide if Australia can harmonise a little closer to the procedures of these aviation powerhouses.