Per-file asset library paths (in addition to preference-defined paths)

I think it makes sense to allow individual blend files to have their own paths to asset libraries, in addition to any 'global' asset libraries as defined in the user preferences.

Use case 1: Project-specific asset library clean-up

Let's say you work on a lot of different projects at once. Each project has an asset library relevant to that project only. When working on one of these projects, you likely do not want to see libraries for all other projects. So, the template blend file for the project would include the path to the relevant asset library, so no management of user preferences is required in the future when switching projects. It also reduces the steps necessary for other users to get set up for working on the project, the asset library is already defined in the project files, no hassle of finding or asking for the right path required.

Use case 2: Character-specific libraries appear when the character is linked into the working file

(This is not exclusive to 'characters', it's just an easy example)

If you link data from a file that has an asset library path defined in it, should that library appear in the file that it was linked in to? I believe it should, as that means you could gain access to a character's pose library or any other relevant assets simply by linking that character. You could have 100 character files, each with their own unique asset library/pose library, but only the libraries that are actually usable and relevant should be shown. If your scene consists of characters Bob and Alice, you shouldn't be seeing the pose libraries for Greg and Steve.

Yes, you could organize everything into nested catalogues to make the large quantities of assets more manageable. But let's say you bring in an extra character to the project from a previous project, or from an external source. This character's assets/poses would likely not have the correct catalogues to neatly integrate into the current project catalogues, adding yet another step of management and clean-up.

Conclusion

Overall, the overhead of managing project/character asset library paths could be improved in my opinion, and I hope this at least gets some discussion going.