NOTICE:
I am not really playing Fallout76 anymore, so this is no longer being updated. If someone wants to take it and run with it the github link below should allow you to do that.

Grim Tech has an updated version here:
https://www.nexusmods.com/fallout76/mods/314

Fallout76CreateCustomIni
Simple command line tool to create a Fallout76Custom.ini for .ba2 mods installed. When run, it will go through your data folder and create a Fallout76custom.ini file that contains all of the .ba2 files it finds. It's really simplistic so that you can add it to the tools thing in vortex or whatever and just run it after installing mods to skip having to edit the custom.ini manually.

I went through a lot of mods and added rules to make sure it put them in the correct spot (sResourceStartUpArchiveList or whatever), but it defaults to putting them in sResourceArchive2List if it's not in any of the lists I've made. So.... it should usually work, but if it doesn't because the mods needs to be listed elsewhere, leave a note here or in github please.

Instructions

• Make sure that Fallout 76 is installed outside of a UAC location (for examples: do not install in Program Files (x86) or directly in C:\).
• Make a backup of your current Fallout76Custom.ini if you have one (usually in Documents/My Games/Fallout 76)
• Install via vortex (using Fallout 76 Extension), or copy the .py or .exe file to your fallout76/data directory
• Run the file from the command line or vortex tools
• Verify the Fallout76Custom.ini looks correct the first few times... maybe....
  

Options

• -h --help Show the help message
• --datafolder Specify fallout76\'s data folder location (Default: current directory)
•  --inifolder Specify the folder where Fallout76Custom.ini lives (Default: C:\Users\[current_user]\Documents\My Games\Fallout 76)
•  --inifilename Specify the filename for the ini (Default: Fallout76Custom.ini)
• --runasadmin Use this to have the program request admin rights if you're having trouble with permissions
• --copyinicontents Copy a file's contents in to your .ini
  

Incompatibilities
Any of the mods that that are really just adding stuff to the Fallout76Custom.ini will still need to have their changes made manually unfortunately.

Github
https://github.com/toopandish/Fallout76CreateCustomIni

FAQ
1. Where do I install this manually?
[Your Fallout 76 Install Directory]\Data

2. Can I run it from there without Vortex?
Yes

3. How do you set this up in Vortex tools?
After installing in [Your Fallout 76 Install Directory]\Data, 1) Dashboard>Add Tool>New...  2) Change Target to [Your Fallout 76 Install Directory]\Data\createCustom.ini 3) Save 4) Run by pressing the play button next to createCustomIni

4. Why does my Fallout76Custom.ini just says [Archive] now and nothing else?
Double-check that you are running createCustomIni from [Your Fallout 76 Install Directory]\Data.

5. I ran the program but nothing changed in my Fallout76Custom.ini file?
Check to see if Fallout76Custom.ini is set to Read Only.  createCustomIni cannot unlock the file unless it is run as an Administrator.

6. After I run Fallout 76 Configuration Tool, createCustomIni doesn't work?
Fallout 76 Configuration Tool locks ini's by default.  Go to Settings and unselect "Set INI to Readonly after Saving".

7. Can I run it from a different location than data?
Yes, you can change the location with the --datafolder parameter. Command line example: createCustomIni.exe --datafolder="C:\path\to\your\directory"

8. When I run the program I just see a black window open and close... is that normal?
Yes, it is just a simple command line tool.  If you want to make sure it works, check your Documents\Fallout 76\Fallout76Custom.ini.  You should see entries there for the .ba2 files you have in your Data folder.

9. This is overwriting my custom rules in Fallout76Custom.ini, what can I do?
You should grab all of your non-modlist rules and put them in another file named whatever you like then point this script to that to file via the --copyinicontents parameter. example: createCustomIni.exe --copyinicontents="c:/path/to/your/file.ini"