@JSGlock34 thanks for that chart. Seems like it might depend on the plate? For instance, I'm using a 19.5 MOS gun, but with FCD plate. RM06, Ameriglo Gl-470's. Does the Lower 1/3 pretty well I think. These are called 2XL. The ones you're saying for lower 1/3 on MOS are 3XL and much higher.
ETA: just measured what Ameriglo is calling "deck height" and I'm getting .320 for my setup.