Base style presets and style transclusion?

[Omikhleia]

For the reminder, the styling paradigm in re·sil·ient works as follows:

1. [One possibly manually copies an existing style file from another project to the target name (...-styles.yml)]
2. One compiles a document and get a [possibly extended] full style file
3. One adapts the style file (to language dependent usage, to document type specifics, etc.)
4. One re-compiles the document.

While it works well, I'd like to consider streamlining at least step 1 and 3.

• Have a repository of sane style fragments, possibly dependent on language (e.g. "fr" footnotes already differently from "en" footnotes)
• Have a way for (top-level) style files to declare the inclusion of a
• Have a way to specify main language and a base style as "class" options

This way, one could use stock presets or put their presets in some common folder, and just declare which to use as basis for a specific document.

Ex.

• Say we have base style "regular" (pick a better name, lol) including a fragment "regular.footnote", and two such fragments "en.regular.footnote" and "fr.regular.footnote"
• User specifies "fr" as langage and "regular" as base style, and all is resolved appropriately to the best match.

So one could skip point (1) wholly, while immediately obtaining a decent styling (even with variations depending on language and whatnot).
There would be less work then in step (3), and more re-usability eventually.

I am wondering whether the above really makes sense and is a nicer direction vs. what we currently have. Being (as far as I know) the only user of advanced features in my own little collection, maybe I too used to it to see the broader picture. (Hence the "question" label).