Hello Michael,
I have made a testnode to check the chain "this.setOutputDatata"-> "this.getInputData" from one node to another. The inputdata are complete available - including named subobjects. So I can use this method to select named subelements for a blendnode:-)
When I have finished the node, I will post it to the forum.
By the way: What is the index 1 -|>Orientations in the blend factory for? And what are the parameters? I didn't find something in the blend.js that helps me.

Thank You very much for your help!

Have a nice day
Karsten