I've gone through various patches mentioned to fix the issue where the parcel does not decrease stock levels for included products and for some reason it's still not working. I've created one shippable product. Then created a "collection of products" product. Configured the included product items to have my 1 shippable product. Once I place an order with my parcel product and complete the transaction in the backoffice, the stock for my shippable product does not decrease.