After investing in a mechanical keyboard & reading Elon Musk's observations about the speed of human I/O, it became clear there's no way around having to just learn an alternative input method besides QUERTY.  It can be done, just like playing an instrument.  The solution isn't custom handwriting.  It might require pressing multiple buttons at the same time to get a single character.  

An idea that came up was a 2 pass interface.  Most keyboard input nowadays relies on autocorrection.  Autocorrection for programming continues to be useless for anything but increasing Apple's valuation.  A similar thing could involve something faster than a keyboard for the 1st pass, maybe an alternative alphabet with fewer letters.  The 2nd pass would always be required & either autocorrect or use a different alphabet with the missing letters.  

Where would the 1st pass end & the 2nd pass begin?  Large function names wouldn't allow word based passes.  Would each letter require 2 taps instead of 1?  It would almost be morse code.  Perhaps a keypad could be shown on a screen with all the current inputs of the current level of a paw interface.  Some inputs would be for descending or ascending a level.  The 5 fingers of a lion paw can actually encode 31 possible characters, but you'd want something more geographically like a querty.