Agree. JL or CX will offer the best experience. Do remember that AA treats Japan (and Korea) as a different region to the rest of Asia so connecting in Tokyo from China to head to Europe wouldn't be allowed whereas connecting in HK from anywhere else in Asia to Europe is allowed. I would be inclined to try to bag a day flight from Asia back to europe (JL offers one flight at around 11am and CX offers a few day flights) in order to maximise the F experience. Both JL and CX usually release seats within a few days of departure. You could also fly HKG-EUR-LHR on CX and BA for the same miles if nothing direct comes up. (Flights to: CDG, FRA, MXP and ZRH all have F cabins.)