A FlyerTalk Posting Legend
Join Date: Sep 2009
Location: Minneapolis: DL DM charter 2.3MM
Programs: A3*Gold, SPG Plat, HyattDiamond, MarriottPP, LHW exAccess, ICI, Raffles Amb, NW PE MM, TWA Gold MM
Posts: 100,403
I would assume that lounge access, or at least the F&B, end upon checkout, including elite guaranteed late checkouts, so I wouldn't normally try to use the lounge after checkout.
However, in some hotels, you're encouraged to check out in the lounge. In these properties, ti would seem normal to then wait in the lounge and use their wifi, computers and printers, coffee and bottled water, etc.
IME in Asian destinations such as SIN and KUL that have many long haul departures around midnight, the hotel seems to assume that you'll use the lounge, including F&B, before leaving for the airport. I've seen people who were not arriving guests using
lounges with luggage in Japan just as I've seen arriving guests be invited to take breakfast in the lounge or later help themselves to beverages while waiting for their rooms to become available.
YMMV