Guys,

so my bet is now on a AA award seat opening up 2-3 days before departure and then going SYD-LAX-SFO.
Of course I will also try to "request" once again the direct flight (QF73) about a week before the anticipated flight.
I am "hedged" with a paid but cancelable booking on another carrier in Y - but hope to catch one award seat. :p

Thanks for your insights and help - really appreciated and once more the proof of a great community and a great forum here at FT.

The process for determining whether to released should be the same regardless of who/what processes the request and not have randomness

The way things should happen and the way things do happen often vary considerably. For example, it would (also) be good to know the criteria that JQ use when they decide to cancel flights so that punters can try to act accordingly.. :)

To give you the final outcome.
The UC spell could not be broken - despite several attempts (the very last one even only 3 days before the flight).
I ended up booking an AA award (via LAX) 36-40 hours before the actual flight. AA releases regularly 1-2 days before the flights some additional seats. I was counting on it and so it was.
So unfortunately no QF award, but I got to where I needed to be.

Cheers
TheAirman