@ kacir,
You mentioned your long use and happiness with using Calibre so I looked at the page for your PocketBook 360 device to see if it is similar to my Kindle K4NT device. If I understand the manual for your reader right, it displays your book holdings on the PocketBook as files or folders containing one or more files.
Is that correct? And to use it do you connect to a storage device or web site and download or copy books to your device? Again storing them in a files or folders and files system like is used in DOS or Windows?
The reason I ask is because that is how I am trying to use the Kindle and it does not work very well. If you read the "detailed answer" info at this link it describes the metadata concept.
Want to change folder structure or file names in the Calibre library? -
https://www.mobileread.com/forums/sh...d.php?t=119175
Jack