Quokka, it's not your fault that you were not trained in the proper procedures for class E or that the proper procedures were never introduced in Australia.
This situation existed because your bosses at Airservices never bothered to ask the FAA how class E worked.
And now 6+ years since class E was introduced in Australia they are still ignorant.
Qantas fly in class E everyday in other parts of the world and never ask ATC the callsign of a VFR aircraft they have been given traffic on.
Why is this so? I suggest you talk to Qantas or any FAA ATC as I am sure you will not accept my explanation.