Hi Troy
Set strategy 50 for a material and create some PIRs. You will observe on MD04 that the PIRs are separated from the rest of the MRP elements on a special stock segment called "Preplanning w/o Assembly".
MRP creates VP planned orders (see note 1595312) under this special stock segment to cover the PIRs.
Generally, it is not a good idea to change these settings, since the standard logic for consumption and reduction of the planning strategies is very complex and may not work after a change in these settings.
BR
Caetano