Dimension specific seeds.

I would like the nether and end to have separate seeds from the overworld.

By changing the end specific seed with NBT edit, novel end chunks could generate after pruning the region files without interfering with overworld generation.

It also add more variety to the already massive collection of worlds to choose from by mixing and matching overworld and nether seeds.

I know this is a feature that only a few people will use or appreciate, but I also know it should be very little work for the devs to implement.