<3x/per day and keep the total daily caffeine intake to under 200mg [2-3mg/kgBW prior to training] is recommended and to have mostly outside of meals in order for any absorption to not be affected by the tannins contained in coffee/tea. Unfortunately there is a lot of variance in the amount of caffeine contained in coffee based on how its made, generally an espresso ~70mg and instant ~50mg per tsp. Tolerance is definitely individual but it is recommended to have outside of sleep times so keep to the morning or times of alertness needed (i.e. training). Milk content being a "problem" is due to the energy density, but we have accounted for this in your snacks so long blacks can be added on top of the plan (theres minimal energy contained in them so they won't hinder progress).