Griffo. You say " the above frequency congestion was well flagged"
Only by people like you who would not accept that there was no need for VFR aircraft to make announcements on ATC frequencies.
You are obviously one of the people behind the scenes driving the present CASA requirement that is opposed by every RAPAC.
For a start Mark Skidmore has said there is no frequency congestion . So the Sheffield deal may not have happened.
And if the NAS was followed all of these unmarked airports would operate on the multicom of 126.7 and there would not be a problem.
Remember the man in charge of airspace at CASA , mr Peter Cromarty is ex British CAA , which has undoubtedly the worst airspace allocation in the world .
Imagine. A decision is made to go to the NAS which is closely based on the North American system so they put someone on from the UK and can't work out why nothing happens!