I would personally look at changing one of the flights.
2 hours is not much all things considered, if on separate tickets. It's true HKG is an extremely efficient airport but Bali flights have been disrupted by volcanic activity in recent months, you are entering typhoon season in Hong Kong and the 777-300 is not an aircraft they desperately need back in HKG.
CX staff in DPS are pretty good though in my experience and i would be surprised if they didn't check you straight through to LHR.