Many technicians question the value of making a mini bulls-eye when repairing cracks.
The reason for creating a mini bulls-eye is to help reduce the effects of the stress in the crack. Stress is a function of force divided by area. The larger an area is, the lesser is the effect that a force can have on it. A bulls-eye has a greater area than does the end of a crack. A mini bulls-eye placed at the end of the crack will reduce the effects of stress and act like an anchor in the crack.