Recipes using multiples of an item are not possible without having full stacks.

[UnlimatedStone9]

Recipes using multiple of the same input are not possible without having full stacks of that item to place into the mortar.

[UnlimatedStone9]

Honestly have no clue what I meant here, I think it was in regards to an issue a while back about being unable to produce recipes that used the same inputs as other recipes, but in different amounts.
So like, a recipe with 4 individual items would overwrite, or be overwritten by a recipe that used 4 stacked items (of the same item).
Hence the "need multiple stacks to achieve the multiple individual items recipes.".