Adjustable height and depth limits of the world

(COMPUTER OVERHEATING WARNING)

Early snapshots of 1.17 have added this feature, where players can extend bedrock down to y=-2032 and build limit up to y=2032, however only through special .json files. This would not only be more room for caves and mountains, but this also means larger, deeper lakes and oceans, and allow the water levels of large lakes, not just tiny ponds of water, and rivers, to be not just at y=62, but anywhere on land. This would add a lot of diversity to the world, but think about being outside of any cave, in the middle of nowhere, but to find out you're below y=0 or even y=-400! I would love to see this feature being implemented as soon as possible.