Just finished mine with CX. I made a couple of concessions to get it to work online, I only lose about 8,000 miles but I also saved $6-700 so it's a win I guess.

A couple of good data points for others booking in the future, this would only affect ex-Japan since YQ/YR is relatively low originating from here. There's always a lot of discussion using AA codes vs QF codes with QF's very high fees on TPAC. On the OW site it doesn't give you codeshare options, so I initially had AA43 AKL-DFW. Before paying (the OW site does look like you'll pay directly there, but they actually end up just giving you a PNR and you have to call for a payment link from CX), I got in touch with CX and checked the price difference to use the QF 4396 code. QF was only 2,000 JPY more (about $15) so I changed it, don't want to risk AAdvantage shafting me trying to credit by revenue method (even though if the AA code credits as distance it's 25% more miles. ) I really wish AAdvantage would give a definitive answer on that.

WhatsApp for CX seems more competent than the phone, but that's only a sample size of 1 so far. The phone agent couldn't do the change to the QF code, said it gave her an error and didn't know how to contact the OneWorld team. WhatsApp agent made the change in 30 seconds and issued a new payment link right away with the very slight price increase.

Overall happy with the ticket I booked but took a lot of fiddling around with the site to get it to work. Also got the very last D availability ex-Japan to AKL on CX for that week I want to leave. (married segment issue, otherwise plenty to HKG or even married segments to SYD). A couple of frustrating points I encountered, it'd only give me this CX flight ex-Japan if I select CX as my preferred airline otherwise it insists I have to use QF to SYD, BNE, or MEL to get to AKL, but that also means my very final leg, MNL-TYO, it won't offer any JL flights, only CX wasting a segment that I could have used somewhere else. I could have remedied that on the phone, but didn't really feel like trying, it's a few hours in the Pier at HKG I guess, not the end of the world. It also errors out with EBB-CAI, for some reason it doesn't see the QR flights, I had to enter those separately but it didn't give me the "waitlist" error that it usually does when you break married segments. I suppose the married segment was available just the OW site can't handle those city pairs directly. It had no problems with EBB-AUH on QR however, so was a bit odd since that's the same region. Unfortunately though the UL deal ex-AUH only has 6 months validity and I needed 7, so have to do the RJ one ex-CAI instead since that's a 12 month validity. Again there, I end up saving a bit of money / miles going that route but despise CAI airport so much I'd rather do UL.

Edit: Forgot to include the price for a data point: DONE5 including CX, QF code on AA, AA, and QR. Total 1,020,000 JPY which hit my credit card at about $6800 thanks to the absolutely awful JPY exchange rate at the moment. I wouldn't be surprised to see these eventually get repriced unless the BOJ pulls their head out of the sand and fixes the yen, so enjoy it while it's still this attractive. If you're booking this with CX, on their payment site it offers to let you pay in your most convenient currency... don't do it, it's just another dynamic conversion scam, it quoted me $7100 which is quite a markup.