Why not shop around the Sydney dealerships to find who will update your iStep for the least cost (assume you didn't buy new which realistically reduces likelihood you'll get it free unless it's to rectify a fault). They may not update free for the PDC change as that was a change to how it operates rather than fixing a fault.
IMO it will be worth a reasonable fee, the biggest improvements are to traction control, steering and throttle (plus you get the PDC change which my LCI already had). If you get it updated just be mindful early on that enthusiastic driving in Sport+ or Traction will be a lot more slippery than what you have now
