If I’m using a soap calculator, I’m pretty successful with my recipes. However, if I add things like goat milk powder, clay, oatmeal and honey, do I need to adjust water & lye? Not necessarily all in the same recipe.
honey is a very small amount of your recipe, so while it does have a small amount of water, I don't bother accounting for it
clay and goats milk powder mixes in better if you use water to wet them first, but that can be taken from your lye water (before you add the lye)