THe difficulty I see, is that like Duke says, in Hero you get what you pay for. It seems like the bane of "soft Magic" is the utility and appearance of consistency of the spells. Similarly, technology is mostly marked by it's consistency (See: Machine guns). THe loose soft feel, that inconsistency would confer just doesn't work with the mathematics of Hero. I leaned into it, set a list of nust have, and can't haves to the advantages and limitations of each culture's magic, to flavor them differently, but they were consistent tools used by the people who could wield it. THe only nod to the airy fairy tuypes of magic were some cultures had invisible power effects and indirect on them. Brandon Sanderson's meditations on magic systems clarified a lot of what I have thought about. The current campaign has no magic at all, but the characters dont know that as a lot of them are superstitious priimitives (Except Alchemy works, so there are healing potions available, otherwise people get too cautious).