Build height is 256 instead of 128 in the Nether

this is normal

If it gets fixed the community would get really upset. Plus it would remove all the builds above the nether roof. If you consider using nether roof cheating - don't go there. 

WAI

This exploit persists

@Stop using my real name (I really don't get how to mention users here...) You can use Misode's data pack generator to produce a custom data pack that allows building only up to 128. Maybe this could indeed be the default in new worlds...

I see this is currently closed as "Works as Intended". Is this really intended (and if so, can anyone point to an official Mojang statement to that effect), or is it really more of a "Won't Fix" because too many people would complain if this were fixed after so many years?

MCPE-18263 Works As Intended. Why is this one also intended?

Close this as "Won't Fix"! Then, it will be a guarantee that this stays forever.

They should add a gamerule on the build limit. 

Here would be a fix to make sure the tall 256 nether height is retained in older saves but the 128 fixed nether height is in newer saves:

There needs to be a world level.dat byte flag called taller_nether. If true, height limit in nether is 256 instead of 128. Defaults to false in newer worlds and true in older worlds. This ensures older saves do not break and therefore can function as before, but newer saves work like Bedrock’s nether ceiling limits. Players are informed if their Nether uses the 256 height or not.