I don't have Fender tips, But I can show you what can happen when I rock hits the fender. Not really sure if the Tip would stop this, and No it didn't start that big, it started at less then an inch, and now it is up to the lisence plate.
I put a stainless steel mudflap on my front fender and it cracked from one of the bolt holes. It wasn't that the fit was off as it wasn't, I think it was the vibration along with the wind load. If I had to do it over again, I'd use a leather or vinyl....Mike
I had chrome tips on my previous shadow, and will eventually be getting them for my current bike as well. I had to drill 2 oblong holes for each tip (front and back of front fender and back of rear fender.) As I remember they were kind of a pain to install but they looked great and I had no problems once they were on.