The tension grips are for the tubing. Not the mainline wire.
After my first tubing install 5 years ago And having to go back and cut all the ties and tension the tubing to keep it from curling around mainline I use these things religiously. Was paying $30 each last time I bought a couple.
I use them combined with an adjustable mainline wire tensioner and am able to loosen them or tighten them if need be.
Has made a huge difference in keeping the tubing straight.