I claim the ornamental design for a cooking grid support ring for kamado-style grill, as shown and described.
FIG. 1 is a top perspective view of the cooking grid support ring;
FIG. 2 is a bottom perspective view of the cooking grid support ring;
FIG. 3 is a top view of the cooking grid support ring;
FIG. 4 is a bottom view of the cooking grid support ring;
FIGS. 5-8 are respective side views of the cooking grid support ring; and,
FIG. 9 is an environmental perspective view of the cooking grid support ring, the broken lines representing a cooking grid and fragmentary portion of a kamado-style grill forming no part of the claimed design.