I haven't posted this incident, but somebody else may wish to.  in both PP2012 and PP2014, one can see that turning off IC eliminates splotches at orthogonal intersections (main problem area for IDL).  however, new component of FFRender adds surface artifacts that resemble bad shadow bias or bad AO settings, even though neither was used.

after they introduced IDL in P7 and P8, I believed that using bevelling or micropolygons at corners would eliminate problem, but I didn't try it because turning off IC was introduced in P9.  whilst nobody turns off IC, it's alot faster now with PP2014, in case they want to adjust FFRender for SR 4.1.