STD only affects FILENAME BASED DEVICES. (
and never, the Calibre Library folder)
The Plugboard, only affects METADATA BASED DEVICES like the Kindle.
The intent of the plugboard is to modify the DEVICE COPY of the book so that it APPEARS to have more metadata fields than it does.
(Series/Series Index is NOT a standard field
like Title, Author. We fake it by cramming additional info into a known area, while leaving the original Library, pure)