The experts will have a more thorough answer, but I believe that nothing you do (except direct intervention by someone with real power at UA) will change it so you get upgraded ahead of a higher status customer once you are on the wait list.

I do believe that if there is no waiting list and there is upgrade availability, then status doesn't matter, it's first come first serve.

Also, UA is VERY tight on upgrade allocations for LAX-SYD and SFO-SYD (and return).

Sorry!