This is a Fabric mod for 1.17+ that changes the Nether and End build limits to match the new Overworld build limit. Namely, blocks can be placed between -64 and 320 y. This mod does not change the world generation at all, just the build limits.
There is also a config file which allows you to fully customize the bottom, top, and logical heights for each dimension.
The All Dimension Height Increase Team
