Just an observation about phantom availability:
People sometimes see classic rewards availability online for particular flights but then find they aren't actually bookable. The conventional wisdom is that the availability shown was a mistake and those award seats didn't actually exist.
I had a recent experience that suggests at least some supposed phantom availability is really a block used by QF to selectively discriminate against people booking OW Award itineraries. In my case of a 318k award, the last flight I wanted to book was QF SYD - MEL at the end of a PMI - LHR - HND - SYD stint home from Europe. That SYD -MEL route has flights departing nearly every half hour and, as you would expect for a domestic flight 340 - 353 days out, nearly all flights were showing J availability.
Our HND - SYD flight will arrive at 06.10. so I wanted a connecting SYD flight departing at 08.30 (but up to 09.30) to keep our transit time to approx. 2 - 3 hrs. Each time I tried to book, the agents told me the earliest availability was 11.00am. Before I tried for the fourth time I went online and made a separate booking for 2 x J on the 9.00 SYD - MEL flight and had no trouble getting it ticketed, confirming that what the agents were telling me was BS.
Next day the same flight, and all the other morning flights, were still showing J availability but, again, the agent said the earliest available was 11.00. I asked her to check further because, with respect, what she was telling me was clearly not correct and she could check my other booking made the day before to confirm that. She then conceded that, yes, there was availability but she "couldn't" book us on them - but declined to explain why. After I said I wanted the 08.30 flight to avoid a long delay in SYD at the end of a 35hr trip from Europe, she said she understood and consulted a supervisor. She soon came back with the news she had got the OK to book me on the 08.30. Problem solved, but it was a problem that shouldn't have existed because I should have been entitled to book those seats from the get go. I suspect QF just didn't want to give J award seats during prime business commuter hours to passengers who are obviously tourists.
That got me thinking whether some other cases of "my system's not showing me availability on that flight, sir" are actually a deliberate construct by QF to restrict access to award seats for people booking OWAs.