This allows you to import an external rig with animations into your current setup. It is useful when you want to transfer the bone/rig structure of another character onto a new target with a similar structure but different appearance. Very helpful when you have lots of similar characters in an actual production setup and you need to transfer rigs and bone motor animation over, resulting in big time savings.
Tutorial:
https://youtu.be/THVFe3tZPD4
Even more amazing features to follow!