I am interested in the best way to get gradebook results into other systems.
Is the local plugin you mentioned for XML Grades available?
It looks like we have never shared that plugin. It is rather OU-specific, so we would not want to properly release it, becuase then people might expect us to support it. However, I will see if we can do a dump of the code, so that you can pick it apart, and use the bits you like in your own plugin.