The Inventory Cache does not cache folders, at all
Currently the saveCache method saves;
const json = {
version: this.version,
items: this.items
};
While inversely, the loadCache method only looks at this.items
However, folders are under this.folders and when loading the inventory via
const inv = bot.clientCommands.inventory.getInventoryRoot();
inv = inv.populate();
You end up with a inv.folders of [] instead of the array of folders you'd expect, so you're basically forced to not use the cache at all if you want your inventory to be usable in any way