Question About Flying Characters, With an Alternate Proposal About Invoking Certain Aspects

Flying is a narrative permission, right? So it is presumed that characters in combat who have the Flying aspect can be in the Sky Above The Battle zone and shoot down on the adjacent All You Non-Flying Losers Below Me zone, and basically shoot at, say, sword-wielding mooks with impunity.

I'm asking this because on the one hand this feels unduly powerful, but on the other hand, I've never been crazy about "Flight" being described as a stunt giving "a +2 to overcome rolls related to flying," which is what I see a lot in the literature, and which feels distinctly unnecessary.

And then I remembered the FAE writeup for Miss Martian, who has a simply ridiculous number of narrative permissions—so many that you could never account for them all with stunts. I mean, I'm glad Fate can handle them, but it still feels like an overbalanced character concept.

Then I got an idea: What if you could spend a Fate point to enable certain unusual permissions? It wouldn't be a stunt; it would just be an additional thing a Fate point could do. Your Sword of Giant Killing insta-kills a giant (essentially giving the player the option of bypassing the stress track for a particular encounter at justified cost), or your Aspect of "I Am a Living Electromagnetic Pulse" to shut down all electronic devices in your zone. Basically, it would be useful for any Aspect which implies an unusually high power level that isn't accurately reflected with a simple +2 to a roll. (Like flying in combat)

Or perhaps, going back to Miss Martian, it COULD be conveyed as a single stunt: "spend a Fate point and enable any of these crazy permissions from telekinesis to shapeshifting to camouflage to regeneration." I guess that could work too. But I prefer the idea of not using up a stunt slot for something that already exists in an Aspect. (Particularly for the Giant-Killing sword. Why spend an entire stunt on something that's not likely to happen that often?)

Of course, as always, what I'm talking about may already exist, and/or the suggestion I'm making may unbalance things. So please weigh in! Thanks.