Good to see a project like that handled elsewhere
When you consider your plugin polished please ping back. We might want to steal some ideas to implement
https://github.com/koreader/koreader/issues/8472
The idea upstream is having a model/view of library items and let plugins provide its own "scan" methods.
That way the calibre plugin within KO could populate the view using calibre metadata. Or a "zotero" kind of plugin could create a "library view" for its articles and stuff.
As far as I can see it everything is fun except crafting UI widgets for the library view. That's what I plan to steal from you