Winching under a specific AOC is quite normal and accepted practice: the AOC would have an Ambulance section which covers winching. Others with winching would be Fire Fighting, Police and SAR; all done to the very highest standard with regular currency checks and practice flights. It is not "Public Transport" in Australia, that would be RPT; we then have Charter and then Aerial Work, all with different criteria.
John it may help SM to understand if you suggest that most of those "sections or functions" sit or fit into our Airwork type of AOC.
That is separate from the carrying of persons for hire or reward as passengers on either a regular route, "RPT" or a random route, "Charter".
POB an airwork flight can only be there as "qualified crew or patients". (intriguing to note that patients are not detailed as such in legislation as far as I know, but of course they cannot be 'passengers' who either pay or are fob on a private op)
We can do private airwork where the entity requiring the work also owns the aircraft.
A lot of that work falls into what is known as a "grey area" with regard to commercial activities as most of those entities are registered for business purposes under the taxation act thus receiving tax relief for all costs, including spare parts for flying machines.
Where charity groups fit is a matter of confusion for me.
Then we have our usual suspects of private operators who illegally seek reward for hire for various activities including charter.
Which is all a rather usual state of affairs for all countries operating under ICAO rules I would assume.