It is now happening at EDI!
Early announcements made for groups to split into 1, 2 and 3 into fast track area. Group 4 to general boarding.
Then called pre boarding followed by Group 1 Just boarding in that group, so no idea how the rest are going.
Only problem was that the length of the 123 line was so long that I could not hear the announcement at the back. When I saw people move I went forward to join Group 1.