Oh, FFS. Yes, you can fit BA's NEW J seat 4 across upstairs on the 747, yes, it also fits 8 across downstairs, yes, some other carriers J seats fit 4 across on tha A320 family, BUT PERHAPS BA's NEW J SEAT DOESN'T. That's all I'm saying. You can come up with counter examples until the cows come home, but we're speculating about a specific J seat on a specific plane.