As you seem quite keen on QR (and understandably so with their excellent product) just remember there's also the 2 transits + 1 stopover per city limit which might limit your QR paths through Doha.
That just got me thinking... I always worked on the concept of only being able to pass through the same transit city twice, but by 2 transits + 1 stopover, does this mean it could theoretically be twice? Say;
SYD-DOH-LHR(x)-DOH-ADD(x)-DOH(x)-HKG-SYD
As much as I don’t want to stop in Doha for the night, if it buys an extra QR option then it could be worth it.