I'm intrigued by the "advice on how to create your own science fantasy tales" bit. I feel like a lot of people go into Starfinder expecting D&D in space (a la Spelljammer), or else something much more akin to true science fiction, and are surprised to see the amount of influence magic and gods and the supernatural have over the game. Science fantasy isn't the best defined genre out there, so a lot of people don't really know what to do with it. Starfinder's greatest strength - it's truly sandbox setting that allows scientific ambition, humanistic ideals, zealous religions and divine power, and Lovecraftian nihilism to exist concurrently and all be equally valid - is also its greatest weakness. There's too much extra thinking ahead involved.

Pathfinder can get away with being a sandbox setting because it can be concisely understood: "sword and sorcery, Lord of the Rings flavor fantasy except God is dead and the reliability of prophecy and fate with him." It's easy to pick up the game and play Pathfinder or even make your own setting from there. With Starfinder, a host of questions require the game master to put in a lot of extra thought ahead of time. What to do with a world where Heaven, the Devil, Cthulhu and space Elon Musk all exist concurrently? How are gods supposed to work in a world where a local drought or plague can be cured with commercial imports and advanced medicine? What effects does magic and the gods have on technological and social progress? How prevalent is magic, and is it more powerful than science? While fantasy has an abundance of pre-made templates giving GMs an idea of what a fantasy world is supposed to look like, science fantasy is a much more amorphous genre. As much as I love Starfinder's setting, I also know a lot of people who prefer to make their own, and often feel at a loss as to how to make a science fantasy world feel cohesive and make best use of the genre's flavor. I think it would be really helpful to have a creative world-building section, a campaign builder, and some talk about how various genres can make best use of science fantasy's unique setting. I really liked the "Corrupted by Shadows" and "Horrow Campaigns" articles in SoS AP1. Did a great job running over the fundamentals of horror with good advice about how science fantasy can interact with it.

That, or a Starfinder Game Master's Guide. I adore Pathfinder's, and I would buy this book in a heartbeat.