Quick note- The tube pre would be adding even more harmonics, so those are really decent fundamentals.
Also, regarding the optical pickups, it's my impression that a light tracking the string would capture mostly the broadest of movements, in this case the fundamentals. Those little eddys going through the string (higher order harmonics, plucking attack) are most likely filtered out. Also, no string pull whatsoever probably doesn't hurt.
I think that's why they put the optical pickup is by the neck; It doesn't matter as far as fundamental goes. It being closer could introduce problems like the strings moving out of range of the pickups, strings hitting the sides of the enclosure, difficulty of use, bla bla bla.
This all adds up to why I think the ultimate bass would be a multi scale neck bass made from one piece of synthetic material with the optical/piezo pickup system.
