Re: A new instrument! (or ..........)
I find it funny to use ergonomics as an argument for this kind of approach. Having played keyboards for several years, I never felt as connected to an instrument as when I'm holding The Stick and grabbing the notes. It feels like it's a part of me.
I've experimented a bit with this kind of horizontal positioning, and even recommended the rotation of the fretboard away from the player to a guy who insisted that he had to have his instrument lying down for medical reasons, but the fact that you have to push "away" off-angle down to the fret is a problem, IMO.
Another re-inventor of the wheel...