We have now fixed the configurable message system. Check our GitHub to see how this is done! The commit has been pushed. The jar is also updated. To update, simply delete your current "xcp-spigot-xxx-beta.jar" file and add the new one.
The configuration will automatically update it self as it has new defaults, so simply go into your config after restarting with the new jar file and you will see new fields. If you do not get this automatic update, then please contact me through the Support in order to get support.