You'll be wasting your time at CX, 4-5 years before the upgrade to JFO (and it's not a guaranteed upgrade too, bare in mind you have to pass the upgrade selection, other airlines won't recognize your cruise relief time in case you failed.)
Hong Kong is one of the most expensive cities in the world, more so than London. Half of your salary would go into paying rent! If you want to move to long-haul, you would be better off applying for the likes of Norwegian, Virgin and BA who known to have previously taken on pilots with prop time.
Working for HX you would be on your literally be on your own, the show is mainly run by mainland Chinese, Malaysian from MAS and Air Asia, Filipino from PAL, and recently some Mexican (not many local except those who failed the upgrade at CX or expats from Europe), consider it as another mainline Chinese airline where pilots who want to go to China but not fit enough for CAAC medical, so ended up in HX to get their free type rating on a widebody before moving off to ME3. HX's parent company are in trouble recently. So you might be applying for a new job soon after joining them...
www.bloomberg (dot) com/news/articles/2018-01-05/hna-units-are-said-to-have-missed-payments-to-more-chinese-banks-jc1t4qfi
As an EASA pilot, I would strongly recommend against joining any airlines in Hong Kong for the time being, there are way too many opportunities in Europe now and uncertainty in the far east. Before you make any move, I strongly suggest you spend some time on this forum. The grass isn't greener on the other side. Good luck!