The widest contrast range would be the difference between a deep blue 47B filter and deep green 61, or, for all practical purposes, a med deep 47 blue and 58 green. Any of these will give a greater contrast effect than a Y versus M filter set, although the extra wiggle room might not actually be needed.
I also have a sharp cutting RGB additive colorhead.
But I totally ignore this or that alleged "grade" equivalents. Even when graded papers were dominant, they differed from one another in specific grade spacing. Simple test strips tell me everything I need to know.
As far as colorhead dial or button settings go, these too differ between brands, and can even be affected by the age and condition of the dichroic filters, or how clean they might or might not be.