It's sole purpose is to protect the delicate stuff inside. If you have a crash of any magnitude at all, the helmet has done it's job if the head inside is still intact.
Helmet will gladly be replaced at that point.
Personally, my Givis have survived a couple drops over the last few years, with nothing but very minor cosmetic scuffs, which would have been much worse on the bike without the bars.
Thankfully I haven't had to test them with anything more serious.
I was knocked off my Worldcrosser in 2014 by an aging myopic driver who turned out in front of me. I got my speed down to about 5 mph before dropping the bike.
Due to the angle of his car the Givi crash bars side swiped his wing (fender?) and drivers door and then hit the road.
The same crash bar took both hits and was totalled but the bike was relatively unscathed.......just a few scratched here and there. I also think the crash bar saved my leg when I hit the car. Both me and the bike were able to ride home
In my book they did their job. They had to be replaced along with the scratched parts. That was not my problem as his insurance was paying!