KeepParallel^TM Clamp
This useful tool "ties" the rail ends together and therefore you avoid making two cuts on your rail after the bend

Why do I have to make otherwise two cuts?
The outer rail has to go a larger distance than the inner rail, hence the inner rail will hang over and we from Train-Li-USA recommend to square the rail ends. Since you bend in a back and forth process the rails slide against each other, and you will typically end up with with the inner rail being longer on both sides of you flextrack, requiring two cuts. KeepParallel will avoid this.