I was in the understanding that QF still had a couple of slots that they'd leased back to BA. Is this still the case? If so, that would help. Otherwise the options left would be: SWZ-LGW or maybe SYD-MAN.
They do but that takes them back up to 4. Pre-COVID, they were only using 2, (QF1/2 and QF9/10). Adding 2 PS flights would mean all 4 slots are used.
Is there any chance QF could put A380 PER-LHR when all the A380's come back into service?
It is theoretically possible though was possible pre-COVID when QF was saying how busy PER-LHR was. They didn't do it then so can't imagine them doing it now.
Would the use of A340's also have been due to CASA's overly cautious approach to ETOPS back then? PER-JNB is shorter than SYD-PEK which is flown with A330 so can't see why this wouldn't be scheduled with a regular A330.
Yes, until about 5 years ago, ETOPS rules made twins to South Africa from AU unattractive as the routing was pushed north. That is the main reason VA pulled out of its MEL-JNB 77W service. The routing they were made to fly meant it took 2 hours longer than it would have were it flown on a A346.
PER-AKL would be a great 321XLR route! Again opportunity to feed into LHR,JNB,FCO at the right yield. Here is hoping for CPT and CDG next.
Realistically, if you are heading to LHR from AKL, there is nothing particularly attractive about going via PER. It is 600kms further than doing the same flight via SIN or via LAX. If you were doing either of these alternative routes, you'd be on a widebody all the way which is likely an improvement over being in a A321 for 7.5 hours.