Patched version of https://www.nexusmods.com/fallout76/mods/698?tab=description Invent O Matic Stash [mansonew2].
Original author is unable to continue developing the mod due to the war in Ukraine.
Fallout 76 has an awfully constrained and restricting inventory stash limit.
Many of us are running several accounts and many characters/mules.
I hired a good mod developer / game programmer to patch the mod to latest version of the game.
The mod itself is now functional.
But the ~10MB database it creates requires a companion website to process the database to a much more user friendly format.
The companion website part of the process is currently sadly broken.

Installation instructions:
Same as https://www.nexusmods.com/fallout76/mods/698?tab=description
Since that page has unclear instructions, I will try to make all steps crystal clear.

Pre-requisite: SFE, and a "patched" version functional with this mod and current (as of 27 September 2024) game version is included in mod files.
Pre-requisite: If you are using the awesome "Save Everything" mod, it unfortunately must be disabled by removing the sResourceArchive2List = SaveEverything.ba2 line.

Installation:
Install SFE or copy the supplied dll to C:\Program Files (x86)\Steam\steamapps\common\Fallout76.

Copy the supplied inventOmaticStashConfig.json and InventOmaticStash-UO.ba2 to C:\Program Files (x86)\Steam\steamapps\common\Fallout76\Data.

Go to C:\Users\REPLACEWITHYOURUSERNAME\Documents\My Games\Fallout 76.
If it does not already exist, you will have to create Fallout76Custom.ini. If it exists, make a backup copy of it.

Within Fallout76Custom.ini, the mod has to be declared to the game.
If this is the only mod you run, it is easy, you just append:
[Archive]
sResourceArchive2List = InventOMaticStash.ba2

if you have more than one mod, I believe each mod listing would be separated by a comma.

Save changes to Fallout76Custom.ini.

Restart the game. Login to game. Be in gameworld.
Go to a container such as your Stashbox. Press R to transfer items to/from container.

You should see new option added on bottom of the screen saying "O) EXTRACT ITEMS". If "O) EXTRACT ITEMS" is NOT on the bottom of your screen while viewing contents of a container, then the mod was not installed correctly, or if you are reading this page way past September 2024, it is possible it broke again and I could not fix it...
Press O or click on that area of HUD to start the export process.

Items preview will start flashing on your screen if mod is working. 
Give mod enough time for it to process all of your items. Do NOT move mouse or click anything. A brief HUD notification should appear informing you that the export is complete, but you can just also wait several minutes after game is responsive to small movements of the mouse and flashing items previews have stopped.

An export of your inventory will be written to C:\Program Files (x86)\Steam\steamapps\common\Fallout76\Data\itemsmod.ini
It is a large text file (several megabytes).

An external website is basically required for easy translation of that database into a nice spreadsheet.
Until a viable website appears, it is almost possible to re-format that file by hand into an almost usable listing showing name of item in one column, and your quantity of that item, in another column.
If you have experience massaging data, you can do it yourself, for me to explain how to use Notepad++, regular expressions, search and replace, LibreOffice Calc, etc would be another hundred steps unfortunately :-(

Since the mod adds several hotkeys to your game, I recommend disabling the mod after you are done with it. Some portions of the mod do very fancy automated movement of inventory, I cannot be held liable for accidental key presses.

I am not a mod developer, I can try to support with regard to dumb questions, I cannot answer any questions about code within this mod, however. I also absolutely do not care about advanced features of this mod. In fact, I would prefer a light version of this mod eventually created, which only exports category of item, name of item, quantity of item, and weight in stash, and exports to a simple .CSV. Any "features" or code related questions would have to be redirected to a mod developer.