make the existing End biomes actually somewhat different

The two End biomes we have now are barely different from each other. Let's fix that!

Maybe the End Highlands would have big cracks/holes in the landscape that lead directly to the void, forcing the player to have to watch their step a bit. There would also be big, spiky mountains on the island and deep valleys, kind of a cool effect and lending to the barren wasteland feel that the End has. Minimal End Cities would generate here, but gateways would generate normally.

The End Midlands would have the chorus plants instead, alongside flatter, smoother terrain that we're used to seeing. This biome would have the most End Cities, and gateways would generate how they normally do.

The End Barrens would be just how they sound: barren. Little-to-no chorus plants, but there would be End Cities and gateways.

And, a suggestion I got from someone else but I thought was very cool, were upside-down islands, being a very rare biome and having no chorus fruit on the top, but on the bottom maybe! It would look like someone just flipped an End Island upside down, which is not only a fun concept, but also hints at some hidden lore...