just some thought about the Moog Guitar
1. it use piezo to get the vibrtao of the strings then amp it to control the driver
2. if there are 6 drivers for each strings, when one string "sustain", the other will not "harmonic"
3. but it seems dont need 6 drivers, 2 will make it, one for the 3 high strings, one for the 3 low strings. based on my experience with the F sustainer, the unwanted "harmonic" generally when you sustain the high strings, then get unwanted suustain from the low strings, 2 drivers for high strings and low strings individually can solve this problem.
4. if not use piezo, one way to make this work is to use a special bridge puickup-- like SD Vintage Rail (inside there are 2 windings- one for 3 high strings, and one for 3 low strings. they are in parallel)
Everything here is base on guess from the pictures and description. I wish I have time to do some experiment.