Instrument, Nav and solo time can be done under RA-Aus.
I agree the nav and solo time would count, as long as the PPL training was non intergrated. However I am not sure there is no instrument training in the RA-Aus syllabus. I know that RAAus does not approve of people attempting to fly IF (training or otherwise) in an RA-Aus rego aircraft.
Same as people who have a PPL or CPL going and flying an RA-Aus rego aircraft without an RAAus Pilot Certificate.