The crafting combinator can be placed between an assembler and a requester or buffer chest and a recipe combinator can be used to then set the requests on the chest to fetch the items needed to build the current recipe. That all works out nicely. But this results in a lot more items getting requested than are needed because any item the crafting combinator places in the assembler gets requested again.

So my idea is that the crafting combinator itself should be setting the requests on the chest using the recipe ingredient counts * number of products and lower the requested amounts by whatever amount it puts into the assembler. In that way the requester chest would request exactly the number of ingredients required to build the requested products.

Note: bot would still bring too much as they sometimes overfill a request but that's just one items or two, not 2000 copper wires like I have now.