private void Init()
        {
            _config = Config.ReadObject<Configuration>();

            if (_config == null)
            {
                Log("Generating Default Config File.");

                LoadDefaultConfig();
            }

            DownloadVanillaDefaults();
            EnsureConfigIntegrity();

            AddCovalenceCommand("stacksizecontroller.setstack", nameof(SetStackCommand),
                "stacksizecontroller.setstack");
            AddCovalenceCommand("stacksizecontroller.setstackcat", nameof(SetStackCategoryCommand),
                "stacksizecontroller.setstackcat");
            AddCovalenceCommand("stacksizecontroller.setallstacks", nameof(SetAllStacksCommand),
                "stacksizecontroller.setallstacks");
            AddCovalenceCommand("stacksizecontroller.itemsearch", nameof(ItemSearchCommand),
                "stacksizecontroller.itemsearch");
            AddCovalenceCommand("stacksizecontroller.listcategories", nameof(ListCategoriesCommand),
                "stacksizecontroller.listcategories");
            AddCovalenceCommand("stacksizecontroller.listcategoryitems", nameof(ListCategoryItemsCommand),
                "stacksizecontroller.listcategoryitems");
            AddCovalenceCommand("stacksizecontroller.vd", nameof(GenerateVanillaStackSizeFileCommand),
                "stacksizecontroller.vd");

            if (plugins.Find("ChestStackMultiplier") != null)
                Unsubscribe(nameof(OnMaxStackable));
        }

https://umod.org/community/chest-stack-multiplier/52243-not-working-with-stack-size-controller
@WhiteThunder

I don't have any power or influence over this plugin. I just haven't the Contributor role as I contributed a change in the past. I've already recommended to the author to remove the hook completely.

Maybe it would be worth asking to pass this plugin on to you? The author seems to have disappeared.