Is PC9 seen as an additional compliance path for SSc2 Development Density and Community Connectivity, or a separate credit?

I did a test count of intersections for a project that should be able to achieve CI SSc2, Community Connectivity. The project is located in Portland, OR, with intersections on 260' centers, so I figured if you can get it anywhere, it would be here.

I discovered, though, that it falls just short (n = 54), because the riverfront and railroad tracks are about an 1/8 mile to the west, and an interstate is an 1/8 mile to the north/northwest. However, the 260' grid is uninterrupted to the northeast, east and south well beyond the 1/4-mile radius: shifting the center of the radius just one block diagonally to the southeast would up the intersection count to 67.

It seems that there could be room for an alternate option that would correct for sites that are in a highly open and connected community, but near geographic barriers on one side: perhaps an option for a given number of intersections within a 1/2-mile radius, with some reduced minimum within the 1/4-mile radius.