This is tied to the absolute path of files in your home directory making it difficult to rebuild with say differing kerning values. It would be nice if it referred to relative paths. At least one path seems to be /home/sacha.local/lib when I assume it ought to be referring to /home/sacha/.local/lib

It would be neat if it referred to relative paths within the repo even nicer if it if evaluating it installed needed python libraries locally so you could clone it. Open it in emacs. Modify. Eval buffer.

Regarding kerning the only thing I think is really off is r followed by e example Here its not as noticeable with a smallish font but becomes more noticeable in a larger headline or title. I'm using it as the font for org headlines.