I did have a destroy outside of layout on my example already. But still exhibited quite a slow frame rate. Not sure if tweaking the variables would help that much really.
That's why I was originally asking about using separate lines and joining them together somehow. Unfortunately I don't currently understand the maths it would take to make that happen.
I guess I'll just have to stick with the animation for now, and hope that some tweaking will reduce its impact on the memory usage.
Thanks again, it was a very trippy example!