I realise this is veering very much into “getting worrying deep into the detail, should probably step away from the internet” territory but here goes…
Every night since the VS21 started leaving LHR at 1905 it’s landed at IAD and parked up at this exact remote stand at the south end of the central apron, quite some way away from the main building. Is this a good or bad thing when it comes to a swift arrival and immigration procedure?