World border/boundary exists at 30 million blocks despite world being functional far beyond this limit

By default, the world boundary exists at exactly 30 million blocks, and the world border a chunk before that. However, via some trivial code modifications, it becomes possible to see that the game functions perfectly out to 33554432 blocks, after which lighting stops working as of 1.14. Despite this, vanilla does not allow the world border to be set past 30 million blocks, forbidding this perfectly usable 3.5 million blocks of terrain from being utilized whatsoever. This could be fixed by simply changing the world boundary's hardcoded size and world border's default size to be at 33554432 blocks instead of the current 30000000.

It may even be possible to move the world boundary out to 67108864 blocks after some minor fixes, if two bits of lighting used for the Y axis are instead dedicated to the X and Z axes instead, which would not have any major effects on gameplay as lighting would still stop working well above the 256 height limit anyway. Alongside this, the generation of mineral veins would also need to be fixed as to use doubles instead of floats, in order to obviate a crash that would occur if attempting to load chunks past 67108864 blocks at the world border (see here: https://www.reddit.com/r/Minecraft/comments/9u9d4i/floats_minecraft_and_the_far_lands/). Alternatively, the ore fix could be ignored and the world boundary simply placed at 60 million or 67 million blocks out to prevent problematic chunks from being loaded. With these fixes in place, up to 36 million more blocks could be made available in the world in each direction at no extra cost.