I wanted to make it a true generator, in C++, so that it's faster. I guess a plugin will either have its features severely limited or it will be slow.
 
Yes it's pretty slow, but it could be worse. It currently does ~85 ch/s, but I don't have any trees or foliage enabled.
 
I think if you enable trees, things will get funky.
 
Yeah I'd have to create my own Tree generator if I want trees in the world.
 
I noticed in that picture of the floating island, the water acts like the bottom of the world is a solid barrier - would it be a good feature to make it not spread out at the bottom of the world like that?
 
It would make allot of sense to do that.
 
Let there be trees:
It's not even decreasing the speed allot

 I get around 5 chunks less per second. The for that is that it doesn't go over chunk borders. All the trees you see are in one chunk.