Figure compares the test particle's velocity v along the z-axis for several radii of a second BMC, explicitly placed at the previously identified stagnation point for a blocker of radius 5R. In contrast to the point-particle assumption, this second BMC now occupies a finite volume-ranging here from 0.5R up to 5R. We keep the central blocker fixed at radius 5R with a substrate consumption flux J -, maintaining the same overall geometry but allowing the second BMC to more strongly or weakly reshape local gradients depending on its size. As shown in the left portion of the figure (negative z), increasing the second BMC's radius tends to smooth the large negative dip in velocity near the blocker's consumption zone, indicating that a larger body at the stagnation point can partially redistribute substrate flux before it reaches the test particle.