The master BOM is attached to the parent as soon as it is created.  However, the specific BOM for an order is attached when the Work Order is created so if you enter a SO, then make changes to the BOM and then convert the SO to WO, the WO will reflect the changes.
 
If you changed something from a type K to a type F, you need to also delete the Kit Component lines from the SO since you will now be pulling the components via the work order process.