The lucky break perk offers a chance to repair armor when you take damage. This definitely seems like it is too good to be true but it has to be good for something? Will using this extend the life of your armor enough to make it worth the effort?
If you are really struggling with armor damage then it will provide you some benefit. It will repair armor now and then but there are better ways to reduce the frequency that you need to repair armor.
Check out the white knight perk. It will make armor more durable and will reduce the cost of repairing it. This will save you a lot of trouble as you won’t have to find as much ballistic fiber to keep your armor in good condition.