As of 1.16.X (not sure of which, but change happened between 1.16 and 1.16.4) snow layers as well as snow blocks break instantly when mined with unenchanted stone shovel. The snow layers with the mod installed do not break instantly even with efficiency V netherite shovel, and it's breaking speed appears unaffected by shovel material/efficiency enchantment. I believe this is unintended behavior. If not, I suggest changing it so snow layers break instantly so as to keep it consistent with vanilla.