Originally Posted by LupineChemist

A lot of the S. America routes require a lot of ground time, I'd say it's highly likely that it's arriving from somewhere in the Americas, going to LHR and back, then heading to S. America in the midnight bank. Also, IB isn't treating the configuration any differently as they have the exact same seat layout so there's no reason to add schedule complexity rather than just treating them as any other 350