A mismatch from elevation would be your responsibility; this is something else, tied to the architecture of terrain generator. Tiles that don't have source data in given resolution have to generate detail artificially. The problem is that neighbor tiles have to match the borders so there are no gapes when the data are further subdivided and fractal-refined. At the moment the mapping tool doesn't properly account for that, and it would create ugly gaps where the mesh doesn't quite fit.