**Disclamer - messing with the .SAV files can easily mess up your game and you will lose ALL progress if it goes wrongly!**

Back-up your save file before attempting to do any edits!

I highly recommend that you do NOT exceed stack limits on any item you are attempting to modify. Doing so will likely result in weird behavior, like every hunter and hunter base disappearing from the map never to return...other items randomly disappearing, and so forth.

This guide was inspired by the guide created by DubWine, however I quickly noticed that it seemed outdated as my save files did not seem to follow what he/she was describing and so decided to figure out how to edit the save files. Once I did I thought I would share the knowledge.

I used this method to spawn in a lot of matches because I got pretty tired of leaving camp and getting back a few minutes too late and having to make another fire start kit and relight the fires in my base. This way I have a stack of matches in each woodburner.

The example below is for lock picks as I felt this would be far more interesting for people but will work for any item.

Make a new storage crate and place it in the world near your other storage crates.

Place 1 of the item into the crate that you want to make more of.

Save and exit the game.

Browse and navigate to the save file, sort by date modified, most recent at the top.
*\SteamLibrary\SteamApps\common\Subsistence\Binaries\Win32

At the top will be a couple of files.
saveFilesList.sav
saveGame10.sav (in my case it was save #10, your number will vary)

You want to edit the file with the number in it, saveGame10.sav in my case.
Use a program like notepad++ and turn on word wrap.

Search for the word storagecrate.

Now here you will need to use a little intuition to find the correct crate. It will have similar world coordinates and be in a similar save file location as your other crates and will likely be the only crate with a single item in it. Hunter bases also have storage crates but you should be able to tell which ones those are as there will be other items in it, in a different location, and will have other hunter labeled buildables near the same variable string.

In any case here is my new crate with my lock pick in it:
{"ObjectArchetype":"ColdGame.Default__ColdBuildable_StorageCrate","Location":"-65629.5547,-2714.1433,142.6989","Rotation":"0,33572,0","AccessModule":{"UpgradesInstalledNames":"","invItems":{"0":{"~":78,"c":79}}}}

You want to pay attention to the last 2 numbers, in this case 78 and 79.
78 is the item number, which in this case 78 is the lock pick. Other items will have a different number (for example the refrigerator is number 18, IIRC).
The second number is what determines the quantity and that quantity is derived from the first number subtracted from the last number, so in this case 78 - 79 = 1.
So I have 1 lock pick.

Changing the last number to 98 (MAX STACK SIZE!):
{"ObjectArchetype":"ColdGame.Default__ColdBuildable_StorageCrate","Location":"-65629.5547,-2714.1433,142.6989","Rotation":"0,33572,0","AccessModule":{"UpgradesInstalledNames":"","invItems":{"0":{"~":78,"c":98}}}}

This gave me 20 lock picks!

Save the file.
Load up the game.
Loot your item from the crate.
If you want, you can place a new item in the crate, save the game, rinse/repeat.

This method works on multiple slots at the same time so you could edit more than 1 item at a time but the risk of mistakes goes up significantly.

You could also conceivably edit the item numbers to spawn in different items but I did not feel like attempting to spawn in every item in the game one by one to make a list and I feel that would end up ruining the game.

Hopefully this is helpful and remember...BACK UP your original save file!