TabTraveller, I see your thinking. However, do you anticipate ground staff actually being able to implement/enforce that? It USED to work that way in JER, where ET pax boarded first by the rear stairs, and only when they were out the way were CE invited to board via the front stairs (which had previously been roped off). Sadly that sensible arrangement expired a few years ago.

Our last LGW-JER involved a bus, which is atypical, and entailed everyone at random picking whichever set of steps they noticed first. Inevitably a fair number had no idea row numbers started at the front, adding to the onboard confusion due to 'contra-flow'. It was a mess!