i have two ideas - either that when you create a world there will be an option to turn bedrock on/off or that it will be off forever. if you get to Y level 0 there will be 3 layers of obsidian, and if you dig through them you will fall to the nether. also the bedrock on top of the nether will not be there- only at the bottom. in the nether the Y level will be negative, and the thing about every 1 block in the overworld is 8 in the nether will be gone. this will not make portals useless since its easier to move mobs with portals and its not easy to get from Y 60 to Y -60 every time you want to go to the nether, but will help people that want to get to the nether as fast as they can (speedrunners etc..) i think this is a good idea because the fact that there is just bedrock at the top of the nether and that you are able to get over that is a little silly to me. being at the nether will still count as being in another diemension and beacons that you place in the overworld wont work at the nether.
NO NO NO NO NO. Nether portals are significant, and are a symbol of progress. adding this would essentially remove that. Now if I had an iron pickaxe, or even a stone pickaxe, I could go down to the nether without even getting diamonds. it would definitely take a long time to get through the obsidian, but it's still possible. also, having the 8-1 block ratio removed would cause a HELL of a lot of problems, and make traveling harder, as basically every large scale transportation center I make is in the nether. HELL NO.