I didn't mean "mutation" as in "the set piece within the game world that designates you as a mutant that can fly", but rather "the mechanical item that costs 6 bonus points and gives you flight". I should've been more clear. I make this distinction because I don't think the "social stigma" was taken into account for balance purposes as far as mutations go.
I also realize that Solar Charms can't do everything. But I think flight should be one of the things they can do. As far as the thematic of "mundane skills over the top", I think "Jump" -> "Fly" is a smaller leap than "Accurate At Shooting Things" -> "Banishing Stuff to Another Plane of Existence".