Due to the linkage with the BA Club - You are better to look at earning with QR and probably doing something a bit odd like a BKK-DOH- [Insert name of cheapest city in Europe/Middle East], as the earnings will likely be far better than Cathay. Alternatively a return to Japan with Japan Airlines would also be a reasonable plan as they earn "normally" on tier points (Cathay does codeshare with them on some routes, that would let you earn more miles, but generally going direct with JAL will give a better flight and more tier points.)

To put this into perspective, I had a HKG-DXB on CX recently that was cheap business (actual routing was DXB-HKG-TFU, Chengdu for about GBP1.5k per person, so good value). The long haul leg earned 463 Tier Points (in P / cheap business). That isn't going to be useful for a tier point run.