I own the cartridge (not DLC) but use a backup (XCI Rev 002). I installed 3 NSP from the net (last update, 01007ef00011f001.nsp, 01007ef00011f002.nsp) and it worked.
I've just tested with bbb-h-afwta dump. It creates a 4,00 Go (4 294 967 296 bytes) on disk but even if i quit xci-cutter, i can't copy this file on my FAT32 formated SD card.
Split 4Gb works but it generates sometimes files that are too big for FAT32 filesystem : 4 294 967 296 bytes on ExFAT drive instead of 4 294 963 200 bytes for other backups, only one extra byte!
Is it normal?