I’ve wanted to make a keyboard, but I’m not sure it’s possible to make something materially better than the kinesis advantage. I switched to it 10 years after my hands would feel numb after typing.
I think I might have some problem other people don’t, but even for normal people, I find it hard to believe that a kinesis wouldn’t be better for them as well.
I’ve seen some split diy keyboards, but none of them have the great concave wells kinesis does. Also the kinesis has macros, key remapping, and easy switching between Dvorak and QWERTY. Being able to type your password with one button is super cool!
Dactyl https://github.com/adereth/dactyl-keyboard is split and curved. Been thinking about building one, though I'd probably use wood as casing material and I know it will be a lot of work, so it may or may not materialize...