The Australian grid presently curtails ~7-18% of production every single day between 11:00 and 14:00.

I believe that incentivizing people to acquire batteries is precisely the purpose of the policy. It's good for the grid for there to be a lot of storage at the edges. As I understand it, the 24kWh cap is subject to annual review, with it being reduced/the policy being soft phased out once curtailment is no longer necessary.