Since you are saying that the PCR is "working fine", perhaps you no longer need WT 3001 in the Input Table after PCR ZGS6.
Do a Payroll Simulation for one employee, with the "Display log" box checked, and look at the Input Table before and after ZGS6.
As for Operation NUM (which has just about as many options as operations RTE and AMT), look at the documentation available through the PCR or t-code pe04. Start with the hyperlink to 6 place "Operands for NUM, RTE, AMT, then follow the hyperlink to "2nd Variant: Table Fields" because that is where operand F is documented, and then the hyperlink to "Date Specifications", and be aware that the documentation will probably vary depending on the Country Code.