I have built an area in the sky in the overworld and have attempted to link to it from the ground through the Nether rather than building ladders and such in the overworld. I've read that the Y coordinate does not need to be translated to the Nether since it doesn't reach as high as the overworld anyways as long as all the portals in the Nether are at the same elevation. There's also a video demonstrating this. Is that false? I drew a diagram to best describe what is happening with the attached coordinates. Both overworld portals work fine going to the corresponding portals in the Nether, however both Nether portals link to the same ground overworld portal.