I love the idea of the need shaping the tool. For similar reasons, I designed a 30-inch scale guitar that could handle the E and A strings from a piccolo bass, and had my luthier make it. So it's tuned like a guitar but with the low strings at bass register. Had to have two tension rods to handle the difference in tension. Works well for finger-picking.
I'm not a virtuoso, but was inspired by some others trying to get more range, especially Charlie Hunter (whose fanned frets are nuts), various metal guys, and the Chapman Stick.
That sounds like a cool instrument, would be interested in hearing what it sounds like, do you have any clips of you playing it?
I like the idea of a guitar that can easily reach lower registers. Whilst 7-string (and in Charlie Hunter's case, 8-string) guitars are possibly more versatile, I'm quite partial to baritone guitars. This sounds beautiful to me: https://www.youtube.com/watch?v=t_06O8XnJQo
Talking of unconventional instruments, you may be interested in hearing these microtonal guitars, I think the second one in particular sounds pretty good: https://www.youtube.com/watch?v=iRsSjh5TTqI
I'm not a virtuoso, but was inspired by some others trying to get more range, especially Charlie Hunter (whose fanned frets are nuts), various metal guys, and the Chapman Stick.