Hiya,
A really time saving feature would be the ability to latch together Note Pitch and Note Mute. Some sort of way to address a Chord track in a more seamless way like a Drum track.
Say you have an empty Chord track running and by turning a step knob it would both un-mute and allow you to change the note. Then if you needed to remove a note you could tap delete.
Obviously the ultimate would be if all the knobs were push knobs since this sort of implementation would be even more intuitive and quick but sadly..
Sorry if I missed these requests in the list!