… The painless turned into an extremely painful ouch!!! ...
Thank you for posting of your experience and the warning to others.
Unfortunately, not constantly monitoring progress (i.e., minute by minute), regardless of the inconvenience, may cause bookings to be lost.
The e-ticket reissue is essential, as without it, we don't have a ticketed itinerary. The bookings are all re-ticketed on each change that is made. Each airline in the revised (rebooked) itinerary needs to provide confirmation, before each reissue, although this is mostly automated. Any hiccup at the QF end regarding inputting the revised details or charges may cause some airlines (and not just CX) to cancel the seats pretty quickly (within hours).
I never accept being told to wait for 24-48 hours, or longer, for the new e-ticket. Bookings may be lost way before then. I now wait for no more than 30 minutes. Yes, under 30 minutes and then phoning again, I've been advised of glitches which would never have allowed re-ticketing until intervention. It may all go smoothly, but I now assume that it won't.
So, just repeating, re-ticketing needs to be constantly monitored and followed up. I've had several glitches with QF input not being done correctly, but managed to get the e-tickets reissued multiple times within 10-15 minutes, each time, once followed up.
Edit: My credit card charges are instantaneous, so I know that something is wrong when the card doesn't get a hit.