It seems hugely unlikely this will be the case, it would be good, if you had a bar with x amount of "points" which it charges up, if it hit top it just does the highest potency like usual but you could hit enter at say 3/10 to do a 3rd potency, 3rd mp usage, 3rd the hate, etc.
Would solve issue and be pretty epic, it would be like having 10 (or x) amount of tiers but with 1 spell.
But ya know, Yoshi wont think of anything smart like this and it will be the case of having like a cure 3, deal with it!