I'm trying to setup the remove tool so that it only allows for the removal of Twig items.

Do I really have to specify all items in the Allowed Entities object and then set them all to false?  Isn't there a way to specify only those I want as true?

EDIT: So I know Javascript and figured I'd have a look at the plugin
On line 1319 is the function that does the check

        bool IsValidEntity(BaseEntity entity)
        {
            var Name = GetName(entity.PrefabName);

            if (rt.ValidEntities.ContainsKey(Name) && !(bool)rt.ValidEntities[Name]) return false;

            var buildingblock = entity.GetComponent<BuildingBlock>();
            if (buildingblock != null)
            {
                if (rt.ValidEntities.ContainsKey(buildingblock.grade.ToString()) && !(bool)rt.ValidEntities[buildingblock.grade.ToString()]) return false;
            }

            return true;
        }

So I modified this function as per below.  What this will now do is check to see if the "Allowed Entities" object contains the buildingblock grade or prefab name (doesn't matter about its true/false value at the moment)   If it contains an allowed entity, it'll remove it if not, it won't.

        bool IsValidEntity(BaseEntity entity)
        {
            var Name = GetName(entity.PrefabName);
            var buildingblock = entity.GetComponent<BuildingBlock>();

            if (rt.ValidEntities.ContainsKey(Name) || (buildingblock != null && rt.ValidEntities.ContainsKey(buildingblock.grade.ToString()))) return true;
            return false;
        }

These examples will mean that only anything made from Twig will be removed (Note: The value of Twigs is ignored at the moment but I'd advise to keep it as true

  "Remove - Normal - Allowed Entities": {
    "Twigs": true
  },

  "Remove - Normal - Allowed Entities": {
    "Twigs": "Yay"
  },