I am aware of a friend who is Emerald and they have managed to secure the first row whilst checking in at the First Wing. They had 2A and the agent checking them in asked if they were happy with the seat and they asked if 1A was available and they were moved to that seat. If you are not successful at check-in and row 1 is available when you board the crew always seem to accommodate and allow customers to move to that row if they ask.