In 3ds max there has always been a feature that lets you weld vertices that were a distance apart. This is something I constantly need when modeling in Plasticity. The weld process in 3ds max automatically finds the 'midpoint of the two vertices, but it would be good if they could be selected and moved to a third point. A case in point where I've needed this feature is when modeling wings on aircraft, which often turns out to be a tricky exercise, particularly on something like an Airbus.

Overall I find the snapping of vertices in Plasticity is not up to it when snapping vertices to lines, which is something that really needs to be addressed.