JustEnoughIDs 1.12.2 is a mod that that removes the limits of items, blocks, and other elements in Minecraft. It uses a chunk format for this.
To be more specific, the mod utilizes the 1.13 chunk format in 1.12 to eliminate those limits. As you know, the game is full of elements that have different functions. However, their IDs come with limits. So now, you can eliminate those limits with this Miscellaneous mod installed. The mod makes use of a blockstate palette when it saves the chunks to NBT. Besides, it utilizes an INT biome array rather than a byte biome array. Because of this, you cannot combine it with other mods. In case there is a combination between them, it will be good for you to report it to the issue tracker. You can also utilize the mod to eliminate a certain mod without damaging the worlds that were crafted with that mod.
Make sure that JustEnoughIDs is still installed in the game to keep your world safe. It will not be able to help you load NotEnoughIDs worlds. It cannot be used with The Lost Cities at present either. For other changes to this, you have to wait for the next launch. Keep in mind that you must install Minecraft Forge for the mod to run in the game.