I haven't flown a VH aeroplane in Oz for many, many years. I have, however, flown foreign registered aircraft in and out on numerous occasions. I know what ICAO requires in R/T and I've used that all the time because that works in most other places on the planet... in one form or another.
The Oz ATCOs seems to recognise the difference when they hear me using ICAO terminology and readbacks, so I've hardly ever had a problem. Maybe it's just that CNS ATCOs know how to treat us "foreigners" eh?
My experience of dealing with ATCOs over the R/T is that they seem to be up to speed with ICAO but, maybe, they get confused when dealing with domestic ops that have to fully comply with the AIP.. whatever that means. Maybe it means not being strictly in conformance with ICAO?
Or maybe I should also comply with the Oz AIP as well?
In any case, I've never had cause to complain about them and, to my knowledge, they haven't had cause to complain about me. Maybe we're just all confused?