(The below is a bit of a trip report for posterity to aid future searchers.)

Not sure if they use different procedures for the (far busier) evening bank, but the transit process for the morning-arrival DL flight was slow and manual. We used the left-most entrance hall when facing the terminal, so there were no stairs as described above. First, be careful not to walk past the very small transfer desk at the end of the hall, where all transfer passengers were assembled. Once the entire plane emptied, we were escorted through immigration (no formalities/visa/passport check required) and into baggage claim.

DESPITE our baggage being checked through, it was cycling 'round on the beltway, so we retrieved it. Our transit 'handler' suggested we just leave it against the wall since it was tagged through and assured us someone would take care of it--not the most comforting assurance, but there weren't any options. Afterwards, we were escorted all the way out of the airport and then back through normal international checkin---again, at no point were any docs checked, but I also didn't try to evade our handler, so not sure if I would have been accosted had I tried to flee.

FWIW, after checkin for KQ we were given passes to the Menzies lounge B747-347B describes above. While certainly a huge step down from the beautiful Aviance lounge in the central shopping area, it is air conditioned, has a fine selection of food and beverages, and a nice view of the tarmac. Pretty luxurious by west African standards, and I certainly wouldn't describe it as a disaster---I've been in far worse clubs in the US! (LAX WC comes to mind...) Plus, free WiFi (which enables me to make this post).