I can confirm HKG transit from SWP to NA as of last August ex.ARN.
I issued OWE4-biz class ticket like below last August in Sweden (TA: Worldwide) and already completed my trip this MAY.

ARN-xLHR-oDXB-xLHR-oNRT-xHKG-oDPS-xHKG-oNRT-oPER-xMEL-oSYD-oPER-xHKG-oJFK-xMIA-oATL-xORD-oSJU-xLAX-xLHR-ARN

Actually I changed this itinerary two times while staying in Tokyo and it final ended up like this.

ARN-xLHR-oDXB-xLHR-oNRT-xHKG-oBKK-xHKG-oNRT-xSYD-oPER-oSYD-oPER-xSYD-xHKG-oJFK-oMBJ-oJFK-xYVR-xDFW-oATL-xSAN-xLGW/LHR-ARN
(SYD-PER roundtrips ACCEPTED! last SEP)

BUT......When I asked similar itinerary ex. JNB this January through AMEX travel, IT WAS REJECTED and I gave it up.
It might depend on the region or TA.
I also want to know if we can do it.
(this is my first post and a bit nervous)

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UA-1P, JL-Premier, CX-Gold