I did more research online and found a few blogs that detailed their experience....so I don't "need" the APEC card to speed my arrival because there is already a special services counter marked "D/P", or there might be a counter marked specifically for TWOV, so I don't need to wait in the general line, and I am less likely to get an inspector who doesn't know how to process a TWOV arrival.

I hope the next entry will be smoother, so that only leaves the China Eastern agents at HK who might give me a hassle as I only have a one-way ticket on them, which then "connects" (4 days later) to the continuation of my UA ticket to Narita, then back to the USA....I would assume, or at least hope they know the rules, but I will have a full TIMATIC printout with me just in case, not to mention add 60 minutes of pad-time just in case I need to escalate.