I travelled through HKG last week with mixed experience.
I travelled on separate tickets QR to HKG from LHR then a 10hr layover and on to SYD with CX on a 2nd ticket. QR took a fair bit of time at LHR to arrange to check our bags right through but persistence & copied of both their & One Worlds website helped when the initial answer was no. This allowed my wife & I to not have to leave the HKG.
When leaving the plane the transit lane isn't clear but follow the crew signs. The transit experience was awful, packed into a small area with hundreds of people, many coughing. Not sure what is was like if you were entering HK but this was certainly wasn't Zero covid.
We have filled in a Health Dec & received the Green QR code (just in case) but didn't need it. As had onwards tickets.
Pier Lounge only available to transit, as mentioned elsewhere Wing open for HK & China originating pax.
Pier lounge was OK, got very busy at times but showers were great & resting area nearby fairly empty. Choice of food & drink very average.
When called to gate it was a free for all, my wife was stuck in the middle of hundreds of coughing passengers. Eventually the Business passengers managed to make their way to the gate.
Flight to SYD was OK.
Kicker from this experience was wife tested +ve for C19 2 days after our time in supposedly Zero Covid HK.
HKG are just coming back to life, they have a long way to go to make it a pleasant experience.