When I entered acces no. 1 last night at terminal 2D and was Let through just after having waived my mobile phone by the lady I asked her "what is it on mobile boarding passes that you look at to see whether the pax is actually allowed to enter acces no. 1?", expecting something along the lines described by nicolas75. But she replied: "Actually I don't see anything. We just assume that people who have their boarding pass on mobile phone are the ones that are entitled to use acces no. 1 lane".

Fantastic. So here's a hint to all of you with no status flying in Y: just get a mobile BP and waive by the people at the entrance of access no. 1. But do not be surprised to find a larger crowd than expected.