I'm actually surprised QF have not found a way yet to reduce the extra leg room at Row 4 by popping in additional row of seats within the aircraft anyhow hence reducing all leg room throughout. It will probably happen!
I recall back in the day when BA operated the 737 400. Row 4 was essentially blocked for elites but made available closer to departure t-24 maybe for all .

Changed days though charges appear to be everywhere or shall we say elite choices on short haul aircraft reduced over the years.

However when I fly VA I do like Row 3. Platinum advantage.

​​​​