Just a minor update here to say that progress continues to be made on this.
I combed through SotC's skill list and extracted every trapping, explicit and implied, for a Big List of Trappings, then culled from there -- renaming, deleting, combining, adding -- for what looks to be a pretty decent selection. Funnily enough, in practical terms, it's really a list of powers. It's just that every real "power" in this conversion will essentially be the equivalent of a Hero multipower, or an M&M framework.
Similarly, some effects are best achieved through what I'm calling Toppings for now, probably because I'm hungry for frozen yogurt. They're essentially advantages and limitations, but severely streamlined into just a few broad categories each, and taking inspiration from SotC's gadget-creation rules. Despite the slight increase in fiddliness these add, I really do believe it's the way to go (for now, anyway). What added crunch there is disappears after character creation, which remains a concept-focused process.
Even still, I have the uneasy feeling that this is how Champions got started. And that way, as far as FATE is concerned, lies madness.
Hopefully sometime in the coming week I can post some sample characters, but before I do that I have to figure out how many points to budget for an "average" superhero. I will, however, enjoy puzzling that out.