Just to clarify - while OW rules specifically state a requirement for an ONWARD qualifying flight from the AP in question, AA FL lounge only requires a qualifying international flight THAT DAY (Emerald or F of course.). (That is, a bit more lax than strict OW rules.) I know this to be true from reading AND experience - frequently access ORD FL when only remaining segment is AE flight home after INTL segment. Or access FL in ord when next seg is domestic First to DFW or JFK -> INTL.