I've had them break and they just fling outwards away from the guitar. Much better than a string breaking right at the tie off where it flips around and dents the finish just behind the bridge (a common injury on flamenco guitars). However I suppose it could happen different and cause quite a scratch. Smooth edges probably would help avoid the possibility of that.
As far as the break angle difference. It was significant enough to compensate for an overly shallow break angle due to having to shave down the bridge (actually notched mine rather than shaving, as it removedls less material and doesn't compromise the saddle slot strength). And perhaps enough that I wouldn't recommend them on a guitar with an already steep break angle as it could become too steep (if that is possible)
One Ring to rule them all, One Ring to find them, One Ring to bring them all, and in the darkness bind them.