Auto join Elements

@Johannes_Meiners

the nodes are great. But i am not really sure how they work. For example: the element.intersectelement. I use it to compare the elements and afterwards look if they are already joined, but then they wont join.
2018-02-01%2008_11_18-Dynamo

and sadly the new nodes wont solve the “already joined” problem. Am i even on the right way?

Regards,
Ammo