I finally got around to seeking out the discussion paper, up till now only relying on the RAPAC convenor's response, and the DP was interesting reading.
As far as I can tell no-one here has posted a link to it, so here goes. If you haven't read it I recommend you do, for a balanced view to the arguments here.
https://www.casa.gov.au/files/dp1610aspdf
https://www.casa.gov.au/files/dp1610asannexapdf