I'm almost always the first foreigner off the plane here so haven't tested using by ABTC inbound.

Outbound the dedicated APEC Lane is always unstaffed. Yesterday, I was rushing to catch a flight and the two lines for exit immigration were very long. So I walked into immigration office to the right showed my card and was processed in the office by a friendly agent in about a minute, he apologized that the APEC line was unstaffed.