The BA situation at NRT is rather mysterious to me. BA refused to move terminals, when the rest of OW moved ... so AA, QF and CX left (and built/are building new lounges in the OW terminal) while BA stayed behind ... presumably to keep their somewhat expensive Terraces lounge there. And BA promptly closed that lounge, and now uses the NW lounge on a contract basis. Rather surprising that they will allow OW benefits in a contract lounge, but perhaps it was part of a deal with the airport. But BA is now so inconvenient at NRT that it simply isn't worth considering using.