extruding brep/brep curves to form hoopsnake joints

Hey guys, I have a hoopsnake script that generates iterations of connected lines. At each of these lines I want to make joints and really how I've approached it is:

Explode Curve -> Spheres at Vertices -> Brep|Brep with piped lines -> Offset Brep|Brep -> Extrude the offset curves using Perp Frames

This last step is my problem - It seems like I'm missing something really basic in getting the extruded joints to pipe towards the vertice (along the Z axis of the perp frame).

P.S in the attached GH file, run the hoopsnake node for it to start up