Sunfish
Drop a PM to Jabawocky. He's coordinating an industry response to that CASA Project, which, according to CASA, is going to 'formalise' the regulatory position you've summarised.
I don't think Part 91 is law yet. The Project aims to amend the current old rules pending Part 91 becoming law in 2003 ... ("Safety through Clarity" is going to be fantastic!)