I was transferring from an Air Canada flight from SYD to MEL, and the VA agent at the domestic transfer desk put me on an earlier flight (my ticket was the equivalent of a "Choice" fare class. Availability is key, of course.

I will try next week when I fly from ADL to SYD; my flight is at 1900 and I am hoping for something in the early afternoon. If not, I am fine walking around ADL for a few hours and catching up on my reading.