When both coach and BE board the 777 through the same door, it tends to be 2L. When there is a separate door for coach to board, then BE tends to board through 1L. During boarding, passengers tend to hesitate and congregate near the door just after they have entered the plane. They're also more likely to use the left aisle and cross over at the front galley rather than crossing over just after entering the aircraft when they have seats on the right side.