The team has made a call to arms on the .org forums asking for help from the community to try and find/replicate a bug.
The author is "currently facing an issue: for some versions of X-Plane now (XP 11 only), I am not able to control datarefs as I used to. As a consequence I can neither control well dynamics of the load nor prevent it into "falling" in the ground."
The post explains the whole process of installing and providing information back. This is a major issue that is preventing the release of the plugin in its final form.
If you can and are willing to help, please do so as this is preventing the team from releasing the final version.