I have asked BA this question - they suggested I phone Hong Kong to get the information. HKG airport says it depends on the airline and can't confirm BA's policy. I thought I might get a faster response here from you frequent flyers.
Has anyone used the BA check-in at the Airport express station in Kowloon? How long before the flight does check-in open and can you check-in your hold luggage at the station? I notice a few airlines allow 24 hours before but BA is not listed on the HKG airport site. I will have a late flight and was wondering if I could check in and then spend an hour or two after check-in looking around Hong Kong before getting the express train out later.