I really like the idea of the mod, but could a toggle setting be added to let users switch between the mod affecting "Only Overworld" or "All dimensions"? ;)

Implemented in v1.20.1-1.1.0.

You can setup overworld only by using the following configuration:

{
  "dimensionTypeFallback": false,
  "dimensionTypes": {
    "minecraft:overworld": true,
    "minecraft:overworld_caves": true,
    "minecraft:the_nether": null,
    "minecraft:the_end": null
  }
}