Also, it’s not that I think Calibre should work in a certain way, but more that a lot of users want to be able to use the app solely as a file converter without using its other library features. I primarily just want to be able to convert Kindle format to EPUB (and sometimes PDF) so that they’re compatible with Apple Books. I currently don’t have a need for the other functions/features that Calibre offers.
It turns out that the “Save to Disk” feature has a similar issue with
filename truncation as the Calibre Library folder, so it doesn’t seem to be useful for my purposes. The “Add from folders and sub-folders” option w/ “Automatically convert added books...” enabled gives me everything I otherwise need.