For LR shooting, you could put a splatter target for better visibility or maybe a caldwell flash bang to indicate hits. The fb would probably have problems with random oscillations triggering false alerts. Doesn't take much to trigger those things as they are designed for steel, but will work on plastic/cardboard as static targets.
So far as durability, my guess is that is pretty fragile, but for lr shooting you should be zero'ed in for the range and it is then a matter of lead from left to right and vice versa. Wind would be another consideration and that would be the biggest fly in the ointment for a system like this.
The sag in that paracord is something else that could present problems over long distance.
Lots of what if's, but looking at the price of the system and 60 day return, I see more + than -. I would be out the shipping $$. Other systems are $$$$$, but there is nothing like the sound of steel and you won't get that with this system. Speed is variable and that is a big plus over fixed 3mph systems. Prices in the $20k for variable speed systems that I have seen.