Well, thats not exactly the point. It is somewhat convoluted.
Exemptions to the standards are easy for CASA to grant within their area of pervue. ASA and CASA have control over the National Carriers.
When International Carriers get involved, per the Chicago Convention, the airport and procedures must meet ICAO standards. Exemptions to these standards are not as easy, as the ICAO stds are, well, lets say, crazy talk anways!
AUS tried to argue the RNP missed to stay the same RNP level as the approach, ie 0.3 RNP approach = 0.3 RNP missed containment areas. (ie ICAO containment assumes the world falls apart when you go missed, and the RNP containment goes from 2x 0.3 RNP or 0.6nm, to 2RNP or 2nm wide.)
Probably still hear the screams....(poor Dirk)