[DNSB]

Also remember that since your Kobo's exposed partition is a FAT32 partition, you have a limited number of directory entries in the root directory. Also a file name that exceeds the old 8.3 style will require long file name entries in the directories at 13 characters per entry which can chew up those 65K entries very rapidly.

For instance, "The Guernsey Literary and Potato Peel Pie Society - Mary Ann Shaffer" at 68 characters will need 6 LFN entries plus the 8.3 entry so will chew up 7 directory entries.