First I want to thank @Balwyn for giving me some sense of how I might do this (and the keyname trigger in the help file is his).
Capture a bang as either bang or double-bang by setting a metronome on the first bang.
If the [f] is at 1 when it hits the next beat then it's a bang. If it's at 2, then it's double-bang.
Me? I am going to use it with my arduino footpedal as well as my usb-keyboard ([keyname]) foot-switches.
I hope you may find a use for it.
Peace and ever-living Music.