I know there are mixed reactions to the Eureka Flag, and many unions have "taken it" for their own, but the history and significance of the original should not be overlooked.
With the recent debacle over the flag in NZ, it's pretty obvious that the current Aus/NZ designs are still acceptable to the majority.
However, I'd like to suggest a variant - just replace the Union jack on the current Ozzie flag with the Eureka flag.
https://en.wikipedia.org/wiki/Eureka_Flag
https://en.wikipedia.org/wiki/Australian_flag_debate
(Interesting comment: The organisation has not consistently supported one design but is opposed to the
Eureka Flag - no reason given???)