Hi,
i tried to use the "All" -Modifier but it has no influence.

"GlobalStackMultiplier": 1.0,
  "CategoryStackMultipliers": {
    "Weapon": 1.0,
    "Construction": 1.0,
    "Items": 1.0,
    "Resources": 1.0,
    "Attire": 1.0,
    "Tool": 1.0,
    "Medical": 1.0,
    "Food": 1.0,
    "Ammunition": 1.0,
    "Traps": 1.0,
    "Misc": 1.0,
    "All": 10.0,
    "Common": 1.0,
    "Component": 1.0,
    "Search": 1.0,
    "Favourite": 1.0,
    "Electrical": 1.0,
    "Fun": 1.0
  },​

I could use the "GlobalStackMultiplier" as well, but i wanted to try the "All"-Category and it does not work for me.
Btw, what should happen if i have "Ressources" on x50 and "All" on x10.
Will "All" (if it would actually work) have higher prio than "Ressources"?

The all category doesn't have any items in it, same as Misc and one or two others I think. stacksizecontroller.listcategories will tell you how many items are in that category. GlobalStackMultiplier is the correct method. This just grabs every defined category whether it has items or not from the game. I'll consider hiding categories without items in the future.