I just wanted to post an update, as it is now just a little more than an hour before the 605p LHR-HKG departure. Whereas the First Class side of the CX lounge was deserted earlier, there are now about 10 people generating a quiet buzz. The Business Class side, on the other hand, is quite full, about as full as the FL gets at peak times. It is not as cramped as the FL, and there still are a couple of workstations available, but one cannot expect to get a grouping of four chairs to oneself.
As for the chocolate cake, it was fine, but I should have listened to christep: given a long flight of CX F food ahead of me, I should have skipped it.