Mate, if you're trying to move your Fonts and/or Applications out of the root directory to free up some space, I'd like to suggest the method I've been using since day 1, which is pretty much the raw command line method BossTool was built on.

Assuming you're on Windows, get the app
PuTTY HERE. With your iPhone hooked onto your WiFi at this stage, run PuTTY and input your iPhone's IP address and click on 'Open'. Type in your iPhone's username 'root' & password 'alpine' when prompted. After you're successfully logged in, run the following commands. Press "Enter" after every line
FOR APPLICATIONS :# mkdir /private/var/Applications
# cp -Rp /Applications/* /private/var/Applications
# mv /Applications /Applications.backup
# ln -s /private/var/Applications/ /Applications
# rm -rf /Applications.backup
FOR FONTS : # mkdir /private/var/Fonts
# cp -Rp /System/Library/Fonts/* /private/var/Fonts
# mv /System/Library/Fonts /System/Library/Fonts.backup
# ln -s /private/var/Fonts/ /System/Library/Fonts
# rm -rf /System/Library/Fonts.backup
Be sure to copy everything EXACTLY as above, down to the cases and spacings. After done, reboot. BossTool should now show the rightfully reduced root partition size as intended in the first place

Good luck, mate!