APS calculation settings and impact on WO inclusion in MRP RESOURCE table

Noticed our APS calculation process is causing a number of WOs to not have Resource steps in the BEAS_MRP_RESOURCE table.  

I believe i've narrowed it down to the last calculation that we run.  

Any WOs that were flagged as PLANNED prior to the last material check calculation are getting missed in the Resource table.  

the settings that i believe are relevant in the APS Calculation Type are as follows:

In the SETUP section:  Time Reservation is set to 'delete completely' ... & ... Calculate only unscheduled is activated

In the Calculate Steps section: Consider Scheduling ID s set to 'at Planned not Calculate'

My understanding is that in this situation, all time reservations on the Resources for WOs are being deleted, and then only the non-PLANNED WOs are getting their newly calculated time reservations saved into the BEAS_MRP_RESOURCE table. 

I thought by changing the Time Reservation field to 'Delete only from affected orders' it would resolve the issue, but I still ran into issues.... to make that field work, I believe you have to have the PLANNED WOs unselected to avoid their time reservations from being deleted.  But then i think they weren't included in the material check properly, even though they were visible in the APS view.

What am I missing?  Also, what is the difference between the Calculate only unscheduled & Consider Scheduling ID fields? (They seem to both be designed to use the PLANNED flag to remove certain WOs from calculation steps?)