I was wondering if it was possible to alter the placement of a biome per dimension, like for example have nether biomes spawn in the overworld?

You can via datapacks. You only need to create output files (not in a superflat world), copy over the json-file of the dimension and delete the first statement

"registry_name": "minecraft:overworld", "dimension": {

including the closing } from the file and add the biomes with the desired attributes to the biomes list.