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CodeVisio - Calibre determines the folder and file names in the library folder, see ==>>
Want to change folder structure or file names in the Calibre library?
And that's not going to change.
Calibre uses its library database is its primary source of information. The author and book folders are only there as a place to store format files, cover images, and metadata backup files. The fact that they are deriived from author names and titles is arbitrary, they could have been database table row numbers.
If you're mainly interested in converting your HTML to an ebook format such as ePub or a Kindle format, you could use of the command line program
ebook-convert and not bother with the library manager, see
Command Line Interface
BR