I got it to a stable 54% by using an
::: spoiler algorithm typing f or d for consonants and vowels respectively in sentences I thought up, switching languages regularly, :::
and a stable 56% by just typing randomly and adjusting my patterns based on the colored output, which might have skewed my results. Certainly a very cool tool, I also liked the explanation linked on the page!
It sounds like NixOS would solve all your problems. And it makes coffee too!