Stretching Worldgen Terrain

Hello all! I'm looking to stretch the terrain of my dimension so it isn't so similar to other dimensions I have made. I've tried some things here and there, such as messing with noise values in world settings such as custom noise within continents. 
However, for whatever reason, only the biomes seem to be changing, and not the terrain noise itself. I am looking to make that noise somehow stretch outwards more, so I can make my terrain wider in general, such as larger plains. Below are some screenshots.