I want to build a mirror chorded keyboard, using an existing split design like a Dactyl or Ergodox, where a modifier on each side gives you the mirrored key (mod+A gives you ', mod+e gives you p, etc.)

I've seen some commercial keyboards like this, but they're incredibly expensive and non-mechanical (mostly geared to people who are disabled/have limited or no use of one hand).

My theory is that the learning curve of a one handed keyboard that is just a mirror would be easier than a totally new layout like the FrogPad or the example linked here.

Reprogramming an existing split model means I could also build both the left/right hand versions and try to learn both.