Originally, my plan was to create smaller single-book settings like Neurospasta, all tied into Ultramodern. It's something I would still like to entertain. People might have read me mention Threshold, which was a space-horror game. I also had Conestoga--which would insert giant mecha, and Shatterways--a low-magic Conan-esque fantasy. The superhero one didn't have much of a setting at that point, and was mostly based off the movie Push.
I truly like that idea of making different settings. You should definitely go for it.
The superpowers setting should not be about superheroes, but regular people who gain amazing powers through a massive event that changes people, places, and things.
I will try to make an outline for a people with powers setting.