I'm not a hardware tinkerer - but if there was a production version of this, I would buy it. But I guess I'm a niche market.
Would be interested to hear about anyone's experience that owns one of these. How do they hold up? How long did it take to get used to using? Would you recommend to a friend?
https://wearables.cc.gatech.edu/projects/twidor/screens.html
For learning, I personally just try to slowly code simple hobby things in vim, with the cheatsheet in the other hand... I tried to make the layout relatively intuitive wherever I could. I also patiently went through all the possible combinations of presses, and tried to group them into categories of easy<->medium<->hard<->impossible, then tried to put esp. the more frequently used keys on the easier combinations/chords.