About 90 mins before landing usually the air show channel on the PTV downloads the planned arrival gate and connecting flight gate assignments (both CX/KA). Suggest you take a look at that and work out where you’re parking and where you need to go, and then figure out which lounge is most convenient.

As others have stated, although CX tend to use 1-4, 61-70, the gate assignments for specific flights are usually random in HKG.