Recovering from bad CDN URLs

Problem/Motivation

I have a site still on Drupal 10.3.11. It uses CKEditor 5 v41.3.1. When enabling this module, it tries to load plugins from (for example) https://cdn.ckeditor.com/ckeditor5/41.3.1/dll/bookmark/bookmark.js, which is a 404. I cannot find any information about what versions/files are hosted on the CDN, when they may have been removed, or anything which might help me construct a better CDN URL.

Also, the UI suggests using libraries/ckeditor5_plugins, but my libraries folder is managed by Composer, and I don't know of a way to make Composer put various npm assets in the structure this plugin expects.

My current best option seems to be to do my own DLL build of the right version of CKEditor, then move random files from its node_modules folder into my theme or a random custom module or something. This seems ugly; is there a better solution?

Steps to reproduce

1. Install this module as well as CKEditor 5 Bookmarks on a Drupal 10.3.11 site
2. Configure a text format to use CKE 5 with the Bookmark button
3. Use that text format and see the editor completely fail to load
4. Check the JS console and see that the default CDN URL fails

Proposed resolution

Anything better than moving random files out of a Node project external to my repo into a random place inside my repo

Remaining tasks

User interface changes

API changes

Data model changes