if you use the virtual sd you are stuck with it though. library entries for sd card are different from those in internal memory. Of course I guess you could work with the database from there and remove the sdcard binding but... from my experience with autoshelf, nickel caches a lot of data and thus does not see the database changes until reboot. it's only, again, actual usb connection when it re-reads the database and thus my autoshelf mod also requires one additional connect-to-pc step :-/
Someone bribe a Kobo developer, give us an API for things