As to whether or not this would increase intraplate or marginal plate stress I really have no idea. If the plates don't move perfectly synchronously with one another there might be a bit of a jostling around per se. If there were, 677.1cm/yr (22 ft./yr) is potentially a lot of increased seismicity / strain within any infrastructure adjacent to or spanning major fault systems, along with subsequent increase in associated natural hazard risks. All that being said, TPW is effectively a decoupling of the fluid outer core to the silicate Earth (mantle and crust) so it really may be a bit of a stretch to think that there may be increased seismicity. Certainly interesting to ponder.