Earlier quoted context omitted.
We need the equivalent of CSS user stylesheets for UX, where user preferences can contextually override publisher/designer preferences. The relationship between the user and other sources of “design input” can be adversarial. Open-source rule engines can help users to negotiate this adversarial space.
> CSS user stylesheets for UX Isn’t this, quite literally, what Gnome Shell Extensions are? https://extensions.gnome.org/
-using the website to install extensions requires both a browser extension and installing chrome-gnome-shell, not installed by default by most distros
-UI to configure extensions is in Tweak Tool, again not installed by default in most distros and full of the things GNOME people don't really want you to touch but will begrudgingly allow
-the second most popular extension is an improved UI for managing extensions
-the API is poorly documented and new releases always break tons of extensions