I've been fine-tuning my forest for way too long and here's what I came up with:

    {
      "0": [
        "CountAdjacentChance eq 1 1 1 0.01",
        "CountAdjacentChance ge 1 2 1 0.03"
      ],
      "1": [
        "SpontaneousChange 2 0.00001",
        "ChangeByBlockAge gt 200 3 0.1",
        "CountAdjacentChance eq 2 1 2 0.4",
        "CountAdjacentChance eq 2 2 2 0.8",
        "CountAdjacentChance ge 2 3 2 1.0"
      ],
      "2": [
        "SpontaneousChange 3 1"
      ],
      "3": [
        "SpontaneousChange 0 0.25"
      ],
      "InitialCondition": "1 0.0005",
      "colorMap": {
        "0": "black",
        "1": "green",
        "2": "red",
        "3": "brown"
      },
      "timeStep": 30
    }