Thinning cuts remove branches to their point of origin. These cuts result in much less regrowth because apical dominance is maintained. Thinning cuts should be used as much as possible to open the canopy, remove unwanted branches and narrow crotches. Wound dressings may make you feel better but don t help plants heal any faster. Do not cut into this branch collar.
Trees heal pruning wounds quicker and better if the cut is made just outside of branch collar.
On the other hand do not leave stubs sticking out beyond this branch collar. A properly pruned plant should not look like it has just been pruned. Make selective cuts to improve the structure and appearance of the plant while maintaining the natural shape and beauty of that particular species or variety. Consider the reason or purpose before cutting begins. By making the pruning cuts in a certain order, the total number of cuts is reduced greatly.