What's the hurry? HKG is actually an airport that you would want to spend extra time at. It has good food, lots of stores, nice views of airplanes from all over the world, nice lounges and even free internet terminals.

It is quite big so it does take time to get between the gates if they are far from each other.

Make sure KA's system has your UA segment information. If your UA flight runs late, they might even show up at the UA gate to get you.