As Shakespeare once said, Much Ado About Nothing
These are not new regs, nor a new CASA interpretation of them. CAAP 42ZC was first published in March 1992, and is but an advisory publication letting us know the limitations of our licence. As with most pilots & operators, we all have our run ins and differences with Authority, but the maintenance permitted by pilots is quite clear cut. Anyone holding a licence should be well aware of what they can & can't do legally - if it doesn't suit the operation, apply for an MA that will only be issued when the pilot is checked out on the action needed.
With the proposed CAR changes coming in, and Class A & B becoming more alike in requirements, be prepared for Class A type issues. Pilots must be approved by the Maintenance Controller to do pre flights, almost no maintenance whatsoever can be approved (even via an MA) by pilots, and remote area ops become a support nightmare