To add to the confusion…
I think what the quoted bits of the CAAP are trying to ‘clarify’ is the frequency that should be used if you are operating at a ‘place’ – to use a neutral term - that is not in ERSA and not marked on charts.
If you are operating in or out of Ma and Pa Kettle’s strip that isn’t in ERSA and not marked on any charts, it seems you should be using the area frequency to make your circuit broadcasts.
If you are operating in or out of a strip that is in ERSA or is marked on charts, you should be using the CTAF specified in ERSA or on the chart or, if no CTAF is specified, 126.7.
This seems to be consistent with AIP ENR 1.1 44.
Dare I say it seems to make sense? If you are operating in and out of a place that isn’t in ERSA and isn’t marked on any chart, aircraft in the vicinity are not going to be listening out for you on 126.7.
If you broadcast “Joining downwind Ma and Pa Kettle’s sheep paddock” on the area frequency, I’m not sure Centre should be complaining.