For me, the key would be to make it a toolkit more than a gazette. I mean, gazette is fine, but, as many people have mentioned, they have their own home table settings. Also, there's a tendency for gazette content to be quite euro-centric, either in placement or perspective. A toolkit would be really great, though, perhaps with example gazette-adjacent content to bring it to life.
While this is perhaps beyond our immediate capabilities, I'd also like to have some real geological advice for how some of these terrains could interact, for verisimilitude. Obviously magic hijinx can change everything, but just some tidbits about the interaction of rivers and forests, of mountains and rainfall, can help people create really rich and immersive environments.