BOM with fixed material consumption

Hello, I am missing a feature for the BOM. For the operations it is possible to select a fixed time for the setup of a work center and a duration per piece for the execution. I need the same function for the Items.
The result would be two items in the list of items . One item with, for example, 300 pieces of material consumption during setup and the other item with material consumption per unit produced. The addition in the doctype would be a check field. Like “for setup”

Which parts of erpnext need to be adapted?

The cost calculation must be adjusted. As a different price applies for each quantity.

What else ?

I am looking for a concept to implement it or are there already projects in this direction