Yes, I didn’t mention that. That is a feature that has been requested and is in the ideas category already: Production Orders - Enhancements. I thought you were just breaking down bulk purchases, such as buying by the barrel and selling by the liter.
I don’t understand quite what you are doing as a workaround. If you purchase a bundle with 3 components and create 3 production orders, are you listing 1/3 of a unit of the bundle as the input on all three production orders?
I think a simpler method is to enter the three output items directly on your purchase invoice. You can order them however you want. For example, create a purchase order (which has no financial or inventory impact) for 10 bolt/nut/washer combinations. When they arrive, raise a purchase invoice for 10 bolts, 10 nuts, and 10 washers. Divide their costs however you think makes sense. (The cost division will be as sensible as what would occur with a production order.) Leave the bundle entirely out of your inventory management process. The fact is, that’s no different than buying a single 200 liter barrel of a product but treating it as 200 1-liter units. Really, it is just a question of how your purchases are packaged.