AA has two boarding channels and they generally do a great job of boarding strictly by group number
This 1-3 malarkey has been in place for at least the last month at Heathrow and abroad and if you're in Group 1 you are now generally queuing and boarding with half the plane.
I've had 12 international BA flights this month and only once has Group 1 been invited to board before Groups 2 & 3
The gate staff were complaining about it at LHR this morning
Idiocy - what is the point of groups if BA is going to board in two phases?