Update:
I was told when checking in at HKG for the HKG-LAX segment that my 1h50m connection was less than the MCT of 2 hours. Of course that's the first I had heard about it, my TA never said anything. I think it was just a friendly warning more than anything else. But I guess it explains why this particular itinerary wouldn't come up as an option on any search engines, unless I forced it with multiple destinations.

Anyway, CX flight arrived about 15 minutes early (would have been earlier but for a long delay in being towed into the gate...). Immigration wasn't too bad, once the agents finished processing a few straggling "Visitors" in the "US Citizens" line, and the walk over to T4 was easy. Dropped my checked bag directly with security/TSA there and the security line wasn't that long either at about 9:45pm (of course I got in the one behind the slowpokes...)