IMPORTANT: Read this description in it's ENTIRETY. If you don't, you will NEVER understand what the mod does, and what does offer. By just installing it, it is USELESS. I have seen people using this mod with the incorrect way.
Mining Dimension: EX
A mod by mdcdi1315, based on the Advanced Mining Dimension mod, extending it and looking far beyond than the original implementation.
IMPORTANT: For versions 2+, the BML mod library is required. For older versions, Balm is required instead.
This mod adds a highly configurable mining dimension - that is, a dimension consisting only of caves.
Its purpose is to be the home for common resources for modpacks that need tons of grinding.
Apart from that it adds a set of new blocks for the dimension and some copper tools for older Minecraft versions, plus some other features focusing on performance to assist with datapack worldgen configurations.
Note also that the mod does not define any ores or gameplay features for the dimension itself - this is left up to you to define. For assisting with this process, documentation is provided here.
If you feel that is too hard for you to create a datapack adding the features you require , consider using the Default MD Experience Data Pack provided along with this project. It contains a default set of features targeting various mods and adds classic biomes already existing in the overworld like Lush or Dripstone caves.
Starting with the Dimension
To start with the dimension, you must create it's dedicated teleporter (Assuming that the datapack you are using has not modified the recipe).
The recipe is this:

After you do that, you have access to the dimension itself.
Differences with the original implementation
This section is for those who are interested about the changes in this mod compared to the original Advanced Mining Dimension mod implementation. Do not read it if you do not care about the changes.
As stated above, this implementation could be considered a fork of the Advanced Mining Dimension mod, but it has been diverged from that in many ways:
-> The original implementation had the teleporter hardcoded. This implementation utilizes a code-clean and efficient teleporting manager for handling the teleporting operations during a Minecraft world session.
-> This mod uses the BML library for eventually making the mod cross-loader. The original is only Forge. It could be also considered that this mod is a modern replacement of that one , since I think that it has not been ported/maintained for the latest Minecraft versions.
-> The mod adds additional blocks and items to the game along with the teleporter.
-> The mod also ships with additional datapack utilities that datapack developers can use. This is done so that someone does not necessarily need to write a new mod. This was not done in the original implementation and was not even in the author's intentions.
-> The mod provides 18 new feature types, all of them useful for many applications. Due to this, the mod does also perform some performance optimizations for it's shipped feature types.
Notes regarding to the mod's data pack utilites
Unlike many other Mining Dimension mods existing out there, this implementation aims to be much more complete that those mods.
To achiveve that, it provides full configurability by data packs. To even complement it further, the mod provides subsystems on most data pack features that make it's development easier and scalable, based on the mods installed on the given Minecraft instance.
It's powerful DCO system allows conditional loading of most data pack features without throwing world loading errors when an in question feature requests something from a mod not loaded in a Minecraft instance. It additionally makes sure that any data associated with an invalidated object (either due to a misconfiguration or a missing mod) will be destroyed, as such improving memory requirements of loading a possibly intricate Mining Dimension datapack that supports a lot of different mods.
Additionally, many alternative, computationally faster, and better types of objects are provided for common tasks, such as features, feature placement, structure processors, structures, loot tables, and others as well in order to deliver a faster and better data pack development experience.
As metioned before, all of these added features to the data packs are designed with better memory and processor management in mind, thus allowing improved chunk generation times.
Apart of these, the mod does also have capabilities to inject spawning data for the Mining Dimension. This is currently done through two custom registries exported to data packs, the Biome Spawn Additions registry, and the Aggressive Spawner registry, that are defined in order to help loading 1. spawns for entities defined by other mods and 2. provide a better spawning system if so required.
Development notes
Version 2 has been reached! Fabric is also now fully supported.
The development status of the mod is thoroughly described here.
Credits
I would like to give special thanks to Max Henkel for his original idea. I somehow started this project while I was writing a datapack for that mod. I later realized that I needed features that the mod did not provide, thus this project is roughly the result of my needs.
Additionally, for the first versions of the mod, I would like to thank BlayTheNinth for the Balm library, which it helped me to make this mod easier due to the mod loader abstractions that it provides.