While it is still unclear what the physical meaning of this locus is, or whether or not is is reasonable to perform the analysis on data originating in differing stress regimes (as described by (1)), the data are showing a focusing that I believe needs a plausible explanation. Whether this explanation will involve a ridge-push mechanism after (8), basal drag from mantle circulation after (10), glacial rebound or, most likely, regional differentiation of a combination of all of these (and more).
It is my belief that the next step in such research is to produce many map subsets and overlay these with maps of various other geologic observations to search for clues as to the underlying source of these patterns. Hotspots, active margins, subduction, retreated glaciation, collision zones, triple junctions, failed third arms, and more could all contribute to such long-scale intra- and inter-plate stress transmission of stress. In the long-shot category I would even hazard that we could gain incite into back-arc spreading and Chinese energy flux centers.