macboy
CAO 82.3.8 and .9 are pretty specific in spelling out the requirements. I would imagine AAS (who ever they are) either kept the seating to 9 seats or applied for an exemption to the above requirements.
I recall that Airnorth in Darwin operated a 208 to the islands, but were required to carry two pilots and could not get relief from the CAO even though the aircraft had an autopilot and a far better avionic suite than the Brasilias
I also have noticed that 208's operate out of Broome on floats single pilot, but I am unsure what seating they have. Perhaps a C208 Ppruner could up date us all.
When I have a chance I will look through the CASA web site to see if any exemptions have been issued