Any idea what happens when trying to copy a >4gb movie file (mkv for instance) ? does DBI also manage to somehow cut in chunks the file why keeping it readable to apps that may want to read it? (such as NXMP video player, or VLC if I boot to Android) ?Yes exfat is still a problem, and will continue to be until Atmosphere reimplements the FS module and fixes the bug(s). Stick to fat32.
The Switch can use files bigger than 4GB on fat32 by splitting them in a folder and setting an attribute. IIRC you can use DBI's MTP server to copy files to the Switch and it should handle this automatically. I believe that should work transparently with homebrew in general, including SoH.