Hi, AFAIK this is not possible using the landscape, since UE stores the heightmap of the landscape in 16bit, meaning you got about 65000 unique height values. You can change how they are distributed via the z-scale but you can’t get more values since you’re limited by the 16bit format. Since GPUs do 16bit math much faster than 32bit, I guess its unlikely that you can easily change the system to store the heightmap at 32bit…
What you maybe could try as a workaround would be to make a seperate landscape for your mountain alone, with the default z-scale at 1 you can then get a 512m high mountain.