I understand the huge effort needed in order to write the plugin.

But, I'm sure that many of us would be interested to have such a feature implemented. A way to save the joints inside the .skp file during export, such that you can re-import those objects inside google earth (by making use of the API) and keeping the physics (together with the joints).

I was thinking maybe we can start a post in order to see if such a feature would be interesting and possible ways how to adapt the google earth api (maybe a plugin?) so that it can understand physics in the same way that SU does by using the sketchyphysics plugin.