Okay, so this isn't that exciting, but I'm excited, so I thought I'd share.
This is a screenshot of a config XML file that I will be including in DF 4.1. I know not everyone will understand XML, so let me explain why I've done this, and what it SHOULD do... hopefully.
In A21, all mods will be loaded from %AppData%/Roaming/7 Days to Die. This directory is a pain in the ass to get to, which isn't good for the end user, and it means you can only run ONE mod... and you can't run vanilla... if you install there.
What this config file will do, is load the Darkess Falls files from D:\DarknessFalls\A20 instead. It will also keep your saves and random gen worlds there, so you won't accidentally load a modded save on vanilla.
Also it means you can play vanilla with your mates, if you want (or need to), or play other mods.
I will do a full tutorial on how it works once I know it's working. But I'm pretty excited. :) I feel this is going to be better for you folks in the future.