Help Rope Attachment on dynamic rope length and Stitching questions

[Balou]

I know it's an old thread but the issue is back and the images are still relevant. 
I updated the plugin recently and I've got the exact same issue about the renderablePositions doing these weird things. I can still see the rope switching between 2 positions if I'm using rope.solver.OnInterpolate, and doing nothing if I'm using rope.OnInterpolate.
It feels like something is overriding my renderablePositions at some point.
Any help really appreciated.
Thanks