I appreciate your response Joe,
I am willing to use Orion but there are some obstacles:
a. The recent version of Orion has compilation problems as mentioned in this post:
In contrary to your response in this post, I wasn't able to debug my project due to compilation errors.
It won't prevent me from using Orion because the project will still work, but it will complicate my development.
I hope these errors will be fixed.
b. The human hand models supplied in V2 are prefabs and it seems I have to use FBX models in order to use the Autorigging scripts.
I tried to use FBX exporter:
But my attempts to extract the FBX from the prefabs failed.
Is it possible to get FBX models for the human hand models or an explanation how to use the Autorigging scripts with prefabs?