Not quite the complete solution maybe, but I have been using split keyboard (Sinc, Quefrency) for a long time and have been lately drifting towards making each

Not quite the complete solution maybe, but I have been using split keyboard (Sinc, Quefrency) for a long time and have been lately drifting towards making each half somewhat independent by using layers/ modifier keys. I am more focused on left hand, but I thought maybe it could be adapted for the right. You don’t need a special Keybaord to try it out, can just used Karabiner Elements (OSX) or Autohotkey (Windows). Lmk if you’d want some template scripts for either, happy to share them with you. I have Caps mapped to Layer-1 which allow me to do CAPS (pinky)+ WSAD (arrows), g(backspace), we (PGup, PGdn), z (enter). Now I don’t want to reach for number keys from [7] to = and I just map them to CAPS + 123456. Recently i realized that I often have reach for the letter keys on the second half (y, n for example for notification windows), so I remapped some letters to those. I am thinking of actually drawing up a layout which will allow me to use the sides interchangeably but still need to figure out which Modifier key to use, that could be as convenient to press with the pinky as Capslock. For the right side I assume it could be same or, possibly even somewhat easier since, depending on the keyboard you’d have more keys reachable with a pinky to experiment with. Alternatively, if you dislike this pinky-centric approach or feel like you’d want to use all the fingers for typing, you could possibly do the same but with a foot pedal as a modifier / layer switcher. I suppose if I was to find myself in a situation where I have to type with just one hand, I’d look into the pedals that can send HID commands (to keep things simple for OS) or even get a couple of those jumbo mechanical keyboard switches and use them as foot-actuated modifiers / layer switchers.