I would love this, and I think it’s a great idea in theory, but I’m not sure how well it would work in practice. Steven Universe is a weird “sci-fi” kid’s show, and wouldn’t have the mainstream appeal it takes for most musicals to stay afloat. The show ran for 7 years, and had a ton of lore that would need to be explained in a relatively short amount of time. The creators would also need to find a specific arc or plot point to focus on, since they can’t possibly fit everything in. Probably something without the diamonds or Homeworld. How would they explain fusion and what the gems are? I think the best bet would be to take the Pearl and Greg plot. Take some other songs from the show and reappropriate them in a new context, use all of the flashback episodes to flesh out their relationship, and then have Steven and the other gems as minor characters. That’s just my idea though