Owain Glyndwr
Turn coordination is provided except in CONF 0
That seems to be a pretty good answer (Once I figured out that centering the ball is a form of turn coordination-even if flying straight and level.
) And yes, you do not need much rudder in most jets in cruise (CONF 0). Therefore it would seem that the Ny input is used solely in higher numbered Configurations for turn coordination.
Since I have seen a number of "unmasking" events in other aircraft, and the switch to ALT2 from Normal law, opens possibilities for unmasking events, I will reserve final judgement. Maybe looking at the yaw trim problem from the other direction, ie Normal law masking a slight out of trim condition rather than Alt 2 law creating a condition.