I sell products by unit, for example (a cup 9,90€) and (mint tea 12,90€). I wanted to create a pack via Shopify but when I have an out of stock on the product (mint tea 12,90€) I have to go in all the packs to put it in out of stock product. I would like to be able to create a pack but use existing products like bundles do. The problem with Bundles is that they do not create a product pack... I have to add the Bundle on an existing product A and it creates a line with write A+B+C = 45€. I just want a pack but that the pack is created via existing products.