Thanks for logging this in MR-3193. As we discussed there, for the benefit of others, this bug is fixed in the latest RhinoWIP.
I’m able to reproduce this one. Logged in RH-43242.
Rhino 6 has better UV Unwrapping than Rhino 5. If you have a Windows machine, test it out in the Rhino Beta for Windows. These features will be in Rhino 6 for Mac in the future.
This would be an issue for @marika_almgren. I’m not sure that Bongo (available only for Rhino for Windows) has the ability to do skeletons the same way as Blender or 3DSMax.
Thanks again for submitting these and going the extra mile and creating YouTrack issues.