Upper left, upper right, and lower left panels: slope profiles of redMaPPer clusters in different redshift and richness bins. The dip features are present in all cluster subsets. Lower right panel: the local minima of the dips in different redshift and richness subsets. We detect a richness dependence in the minimum radii, but no significant redshift evolution. The dashed lines show the fitted linear relations between the minimum radii and cluster richness at their median redshifts.