You are right, a real odd block with gaps etc makes selecting a point to use hard, CIV3D has shrinkwrap and there is a commercial program to create a boundary around objects so a pointer line could be added and trimmed at invisible edge.
Used this on point num bubble where line is trimmed to the bubble but can be any direction.
It may be for "often encounter blocks with various shapes of symbols" a couple of different styles of labelling. But again trimming around a block shape is hard.
A lot of people are looking for this so very useful.