Another call from CSA today in response to objections I posted to their contact us section.
I spoke to a pleasant women who at least gave some sense of empathy if not any ability to change anything.

It seems as though the only hope of change is if the pollies start taking the issue serious - aaaahhhh!

Of interest CSA don't seem to have any mechanism to give feedback to the Government on how well the system works (or does not work). They can read my points of concern, they can emphasis with my concerns but I still get stung, my ex continues to profit at my expense from my son and the Government apparently does not get feedback from those in the best position to collect "client" feedback.

The formula is government mandated and they can not deviate except in a limited range of circumstances which don't include fairness provisions.

What should be done (in case any pollies read this)
1/ Ditch the whole thing, the conflict CSA generates between parents is not worth it. The good parents will support their kids and I doubt that CSA gets many of the bad ones anyway. Decent parents on both sides of CSA suffer if the other parent is good at playing the system.

I doubt that is politically viable to drop the system so
2/ a. Set a minimum share of a reasonable cost of the care of children shared by both parents regardless of their taxable income. Both parents should be responsible for the upkeep of their children not just the one unfortunate enough to be separated from their kids. A history of dodging real work should not absolve someone from responsibility for the cost of the care of their kids.
   b.   Allow for variations in the allowed amount (not the share) where there is reason to do so related to necessary costs of raising the kids
      - Out of hours care costs related for care to allow for the custodial parent to work
      - Special medical needs
      - Agreed extra curricular activities

Above all never ever allow the system to be used by a greedy parent to financially punish the other parent for perceived hurts from the past.