Just wanted to report back with my absolutely agonizing experience with booking QF F with AA miles:
I had been scoping out US QF F availability for mid-December for the last few weeks. Each day I kept on checking and watched as the inventory dwindled slowly, and all that was left was a solitary LAX-MEL seat on the 15th. Crossed my fingers and hoped it didn't disappear when the booking window for AA opened.
At a few seconds past midnight on the 18th (today), I saw the seat available on AA.com, but it would error out if I clicked it on the schedule citing that it was more than 331 days out. I found a way to get it to display by adding the connectors from YYZ. The problem was actually booking it - it would give me an error of the flight being unavailable each time I clicked through. Called to no avail almost every 30 minutes, was told there wasn't any availability.
A glimmer of hope came when I could click through and got through the passenger information page and the confirmation screen to confirm the hold. Except, the system would error out after that screen.
This game went on for about 9 hours - I tried almost every 5 or 10 minutes, eventually I was so tired I took short 30 minute naps at my desk and hoped no one had nabbed the seat in the interim.
Finally after (probably no fewer than 100 attempts) - the click through worked at about 12:15pm and thankfully, I secured the only ex-LAX QF F seat to be available to AA during the peak OZ summer season.
I think I'm about to go insane.
TL;DR: I spent 12 hours at my computer constantly hitting refresh and calling AA to secure one measly F seat.