citeproc-el VS org-roam-bibtex

As far as I know there is no support for docx export (at least without external tools like pandoc), but if ODT is an option for this kind of embedding metadata within the citations then feel free to open a feature request at the citeproc-el repository and I'll try to look into the problem.

Well, it is sort of doable with the csl org-cite export processor and citeproc-el if one uses the org-bibtex export format, see https://github.com/andras-simonyi/citeproc-el/wiki/Inline-bibliographies-with-Org. The problem is that the rest of the ecosystem doesn't really support org-bibtex, see, e.g., this discussion: https://github.com/bdarcus/citar/issues/397

This link refers to a very old, deprecated citeproc that was experimental in org-ref v2. It no longer exists in v3, and has been replaced by https://github.com/andras-simonyi/citeproc-el. The newer documentation is at https://github.com/jkitchin/org-ref/blob/master/org-ref.org#other-formats-using-csl.

In addition to org-roam, I would recommend checking out https://github.com/org-roam/org-roam-bibtex for attaching notes to specific papers that are indexed by an application like Zotero. Some good tutorials for it are here: https://rgoswami.me/posts/org-note-workflow/ and https://blog.jethro.dev/posts/how_to_take_smart_notes_org/ and https://emacsconf.org/2020/talks/17/ . Since current org-roam (post-v2) uses the normal org-mode "id" form, you can make any "headline" into an roam-registered node. You could then split your long derivations into different headlines, where the body of the headline or descriptive text could refer to prior nodes, but any latex is inserted using org latex blocks https://orgmode.org/worg/org-contrib/babel/languages/ob-doc-LaTeX.html . You've maybe already considered this (and I wouldn't be surprised if local references were easier to do in straight latex), but org-roam-bibtex is really nice for interfacing with your citation system for other papers.

I think you should also look org-roam and org-roam-bibtex (I can't configure org-roam-bibtex properly because I'm on Windows).

Taking this one step further, if you use the excellent org-roam package (which if you don't you should definitely check it out, its great for note-taking), there is a package called org-roam-bibtex which communicates very well with the aforementioned packages. With it, you can create bibliographic notes as part of your org-roam repository from their bibtex entry and initialize the file to also include a link to the pdf from org-noter. Once you learn it, its a very powerful and streamlined workflow for working with articles which makes your life very easy. Its quite a bit of reading to do on your end on how to make all these work together, but trust me its worth it.

Have you followed the discussion here: https://github.com/org-roam/org-roam-bibtex/issues/159

If you want to use it primarily for literature notes, maybe you should have a look at the current state of https://github.com/org-roam/org-roam-bibtex/tree/org-roam-v2 before deciding.