It is true that is more correct (see https://github.com/pcwalton/pathfinder/issues/142). But my motivation is much more user interface than document rendering, so it's quite reasonable to tell the UI designers, "don't do that," especially if the flip side is butter-smooth performance.
Agreed, and there are some deep issues, for example the rendering of very thin strokes which is quite dependent on resolution. Also keep in mind that the 4x4 oversampling you mentioned does not give nice smooth edges. I'm working on font editing, so the quality and smoothness of the line, to most accurately represent the shape without artifacts, is paramount.
