The "usual" CMB transit process is that you walk to the end of the pier where the transit desks are, show your passport and grab the boarding pass there. If you don't have the boarding pass for the turnaround sector from HKG, it's a 5-10 minute process max. I'm not sure if CX uses the same gate all the time, but the last time I came in, it was at the very end of the pier so the walk is the majority of the time. CMB is small so it's pretty straightforward. I had a connection there from CX to UL which was under MCT, separate tickets, and I arrived at the transit desk at 55 minutes instead of the required 60, and they reopened the flight to get me my boarding pass, without a word of complaint.