Automatic coping with dynamo

Since the first time I created a truss in Revit years ago I didn't like that I have to manually apply coping in order to make things look right. So it was one of the first things I tried to accomplish with Dynamo.
 If you're familiar with dynamo maybe you know in the Clockwork package there is a "FamilyInstance.AddCoping" node. The problem with the node is it expects the number of beams to be cut and the number of the cutting beams to be the same. This is the reason it doesn't work for trusses. So I made a simple correction to the python script in the node.

Then when beams are coped I set the coping distance to whatever I want.

However, I failed to automatically set the start and end extensions of the beams.  I did create a node to set the parameters but in Revit it had some strange behaviour. I then added a node to unpin the beams first, but nothing changed. I am very very open to suggestions here.

 So the definition works that way:
 1. In Revit we select all the beams we need to extend and set manually (I am crying) the extensions (all at once).
 2. In Dynamo we select the family types for the cutting beams and the cut beams.
 3. We type the value of the coping distance we want.
That's it.