Above Hell Dimension

It's mainly made for optimization

and the possibility to build on top

of the nether roof like in java,

 but it has it's downsides

First one being I can't remove

the no build limit because it's 

Hardcoded in Minecraft bedrock 

without getting chunk corruptions or

chunks rendering empty

But the best part is nether is less laggy

and you can travel on top of the nether

safely if you know how to break bedrock.