Move spline attached to gameobject.

[Juwdah]

Regarding the performance, I will take a look at this and answer you later.
Regarding the generator being one frame behind, I couldn't reproduce the issue with my test scene, so the solution I am going to give you is not tested: try set the spline "Update In" setting of your splines to Late Update.

Thanks!
I'm afraid Late update doesn't do the trick.

Here's a gif showing the lagg-behind in the rope and then the extra frame at the end:

https://i.imgur.com/zxEtOEM.gifv