While mining, I noticed something strange on my skylands world: low height ores don't generate properly and that include modded ones - except on structures like the villages because they can spawn with stone and below the default skylands height, making possible to generate ores like diamond, lapis lazulli, redstone, etc.

Skylands terrain don't generate below y28* ~ 20, thus, ores mentioned above, respectively, and maybe can solve this by offset the ore generation? (idk if it is possible, i'm just thinking)

I'll look into it, but I don't really see a solution unfortunately, as the biome types are generalized across all the world types and it would be a pain to duplicate everything but with lower generating ores just for the Skylands world type. I'm also not sure if I can modify ore generation at runtime.

And if you lower the entire terrain height? So you don't need to tweak the ore generation, however, i don't know if can cause some major problem.
I don't know and I wish you could find a good solution, because this world type is so cool.
Good luck. Love your mod.