Okay, back to the AIP SUP.....
a. must broadcast their intentions to Avalon TWR prior to entry;
and
b. must maintain two way communications with Avalon TWR within
Class E CTA and notify any changes to intentions;
The ICAO Definition of a "Broadcast" is:
A transmission of information relating to air navigation that is not addressed to a specific station or stations (ICAO)
So, by definition, our VFR's broadcast goes out and a response is not required .. as it isn't directed at anyone.
Then, our VFR has to maintain 2 way comms with AV ... but no procedure for establishing 2-way comms has been published.
By mixing their terms, they are trying to get around the fact that they have established D/C ... not E.
In fact, what they have done is created an utterly unacceptable ambiguity.
What happens if the VFR doesn't get a reply from AV TWR, which, according to ICAO, he shouldn't expect anyway?
What they need to do is re-write the AIP SUP to say ... you must "Contact" the TWR.
You can't have it both ways CASA.