A little idea:
Mute- when you mute an automation lane ,a slider (splitted or not) appears on the right side so that you can enter a value without opening its property window.
Solo- to solo an output of a contraption, an envelope of southpole, a drum line there must be crossboxes in the propertyframe. Even knobs could be useful: You hear the output of the contraption AND the soundout. This way the following connections doesn't receive data from the contraption output, so that the soundout doesn't receive this data and you hear it not twice.
With the knob you fade out/in the soundout.
Maybe the knob apears after the crossbox
Remember a real bypass