How to think about dry additions with respect to flour?
Something that I would love to understand better when build a sourdough recipe. Standard recipe calculators provide you a flour amount for a target dough hydration level.
If I want to add a dry (powdered) seasoning/flavouring, for example garlic powder, milk powder, etc. Does the amount of the added dry ingredients take from the flour amount or not?
For example, using Volodymyr Agafonkin's recipe calculator a 810g pre-bake dough at 80% hydration, 2.2% salt, 20% starter yields a 400g flour, 311g water, 89g starter and 9.8g salt bill.
If I want to add 8% milk powder, would I go with 400g flour + 32g milk powder or go with 368g flour and 32g milk powder?
I am trying to understand if adding dry seasonings tweaks the starting flour bill or is outside of the flour bill?
A supplemental question for dry additions; Are there any additional considerations for the dough hydration level when added (typically) non-fermentable dry additions?
Obviously I am seeking standard repeatable results in-order to play with dry additions.