I agree that there are too many factors involved in nutrition for their to be a one size fits all recipe if you will. The studies and experiences we read about should simply be used as data points to be aware of on your own supplement journey.
Unlike vitamins where toxicity is generally low, minerals have a much narrower "sweet spot". The good thing about minerals though is generally there are some very apparent side effects one will readily notice when intake is too high and symptoms generally resolve rapidly when high doses are discontinued.