I love everything you suggest!
I hope you continue to develop it and I'm sure many will implement it as a base in their games.
I would like to take the opportunity to ask a question about how the mods that add stones work (also layers or biomes ones).
Are they applicable to worlds that I have already been using?
That is, in minetest the blocks are not already generated when creating the world?
Or are they generated every time I open the game?
Mods like these modify existing blocks?
What happens if I remove the mod later?
Sorry for so many questions, but I see that you have put a very detailed description that leads me to think that you know what I am talking about.
From already thank you very much.