I agree. If you don't add ROE to all of your fats up front, then you might want to add enough ROE to your soap batch to cover the untreated fats. I generally don't bother, since the untreated fat in my recipe is only a small % of the total fat. If you have to err when using antioxidants, it's better to underdose than overdose. Too much antioxidant can actually accelerate oxidation of the fat -- exactly what you don't want.