Just an FYI for UA flyers who like to lounge-hop at LHR: I got turned away from AC today on the basis of a “3 hours before flight” rule. Never heard that one before at any *A lounge (maybe this LHR AC rule has been mentioned already in this thread — I didn’t bother to read back through the whole thing). Went across the corridor to SQ (no such rule there), then back to AC once within 3 hours.