I am not sure, of what exactly is the issue that COGS Split document has not been generated. However, there is a functionality since S/4HANA 1809 to create subsequently the COGS Split document. Please refer the
1. If VPRS - You will have to write a routine (Exit) in SD whereby they make the Value of VPRS to zero if the Plant = 1000 2. If Cost Component Split - Dont assign Costing Keys in KE4J.. Assign Costing Keys in KEPC to Plant + Mat type combination... Here, you will assign ...