Q:  Can users leave parts removed through ECO in the kit for costing purposes?

A:     The ECO won't remove parts, if you click that specific work order to take effect to use the new created assembly (with parts removed), you will have to click "Update Kit" button in Kit module in order to remove the parts, and if you have issued parts already, the system will ask you where you want to put those qty.   (This is if the parts are already pulled for the kit before the ECO was approved).