Katharsus, I do not design bonsai, I design trees. Therefore it is not always a good idea to judge my creations with bonsai rules. But you are right this spot could be better while it does not really bother me. Good news is that with continuing what I am already douing for the next ten to twenty years it will disappear by itself. Inverse taper can be corrected by thickening. Thickening happens with sap flow from the top, from the leaves. The more leaves the more sap flow, the more thickening. With the hedge pruning method you have it all.