Rain shadows

With the new Minecraft 1.18 Mountains I think rain shadows are a good idea. On one side of a mountain, any random biome would generate. But on the other side, a warmer biome, colder biome, or more humid would spawn similar to real life. This means that on one side of the mountain there would be a biome like a tundra, desert, mesa, swamp, jungle, savanna, etc.
I think there should also be a chance for mountains to spawn without rain shadows.