I don't think jsfrSE has been to the Arrival. You don't want to go there. It is crowded and hot. There is a nice little sitting area of, oh, 6? A bar-like area facing a wall. The whole thing cannot be bigger than 30 square meters.

I would suggest flying CX from HKG in F, so you can use the lounges, but then on your way back in J it wouldn't be as nice, and you always should ramp up the experience.
So the best plan would be to sign up for AA status match, fly JL round-trip in J, and by the end you will be AA EXP and thus able to use the F lounges at HKG anytime you fly in the future!