I am not sure about this one, I have never played any Korean games, anyone can confirm?
You can convert the HDD on the fly :
https://gbatemp.net/threads/wbfs2fat-py.291320/
of course, a backup is always a good idea as nothing is 100% safe.
If your HDD really has problems in FAT32 with usbloadergx, your softmod might be outdated. Post a
syscheck and see.
As a last resort, you can use
WIT to manage you WBFS partition - good luck with command line tools... There are some front ends out there for WIT, but I have never messed with those.
WBFS partition can only be used with Wii games, Fat32 can be used with most homebrew, Wii games, gamecube games and most emulators. The benefit is obvious.