Thanks for the advice. It did come in handy - especially the location of the ticket desk at HKIA. Not the easiest thing to find if you don't know where you are going.

Ended up popping up to the Ticketting counter at HKIA on my arrival into HKG after clearing customs. There it was a simple task of showing my credit card and collecting the paper ticket. The flight was still a few days away, but they had no issues with giving me the ticket. I think they printed it on the spot, but can't be entirely sure.

With that I had no issues checking in through the ITCI.

So all worked out well.