Just to calrify your sample file...

Given the below settings...

      "Limits Global": {
        "foundation": 50,
        "assets/prefabs/building core/roof/roof.prefab": 50,
        "assets/prefabs/deployable/furnace/furnace.prefab": 5,
        "*": 1000
      },​

Does the Everything (*) x 1000 exclude the other items listed by name (i.e., roofs & furnaces)?

Or is this inclusive?  That is, I have palced 50 foundations so I only have 950 other items left to place?