Super Backflush with Process items

We are making manufactured item: P101 - Drop Sorter Head Support. It consists of P101-A, P101-B, P101-C, P101-D, P101-E, P101-F. P101 is too big to fit on a truck. So we ship it disassembled as P101-A, P101-B, ... P101-F items. P101-A, P101-B, etc are finished good stock items. P101 is a process non-stock item. P101-A through P101-F have demand. MRP generates single work order for P101 based on the process Co/By planning table. Works good this way.

If I use P31114 for WO completions on my P101 work order - it works as expected. I keep completed quantity at 0 on P31114. It still opens up P31115 form where I can specify the quantity produced for particular Co/By item. Say I have made P101-A - I specify "1" for P101-A. I keep everything else at zero. P101-A is produced. Good.