Quick Comment
Boss chose not to install a DC power connector (9Volt).
This forces the user to power the device with a battery and when a jack (audio) is inserted the AB switch constantly draws power which obviously dramatically shortens the battery life. I am not going to constantly unplug my audio jacks as I use the AB in my studio rather than on the road.
This is so much a problem that I am considering installing a custom DC plug (and a couple of resistors) to power the unit from a DC adapter.
Adding the feature would hardly have cost Boss anything so I think this is really a bad strategic choice on their part.