You just need to copy the Lunar Knights line in the romlist and change the CRC hash to the new one. It detected fine and used the same filesize and everything but it just won't load.
I've tried to make my own undub with DSlazy but after I unpacked everything, swapped files, repacked it, patched it (even tried without patching) and then loaded it, I only get a black screen.
EDIT:
Using EZ4 btw.