Just an update of my experience at HKG trying to get a DONE4 ticket reissued (after flying the first segment). Bottom line: CX was quite efficient in handling my situation, which was simply changing some dates and some destinations for flights downstream.

Upon arrival at HKG, I proceeded to transfer desk in E1. CX agent suggest I settle down in Wing First Lounge and then go land side (She gave me a "Transit Advice" form) to get ticket sorted.

While at Wing First, I gave a copy of my revised itinerary to a staff, who then handed it over to another person. That person told me just sit in the lounge and be available if she calls.

Some 2.5 hours later, I checked the status. She was assigned somewhere else in the airport, so another staff called for me. I was told all changes were made without problem, except for my requested seats. I was handed a phone to talk to the agent regarding credit card charge details. I paid US$125 as change fee per pax. The other charges (YR, YQ etc...) was very minimal and was charged in ZAR.

25 minutes later, I received my reissued ticket in my email. When it's time to go land side to get BP and check bag at UL counter, we did so by showing the "Transit Advice" form.

The key here is that I had plenty of time at HKG (8 hours before my next flight) to make the change work.

Thank all you guys for chiming in with suggestions and sharing experiences.