Process Order GR & GI Scenarios

Scenario 1

Say Process Order Qty 100 .

Did a partial GR (MIGO for qty 50), and then manually set Final Delivery flag. Did another partial GR (MIGO), but did not reach full order quantity. The Final Delivery was then unchecked by the system as a result of the second GR. Do we have any SAP note which describes why system removes the DLV flag during second GR (which was set manually & saved after 1^st GR)

Scenario 2

I have issued all components required against a Process Order. Hence there is no open reservation against any component .Now  If I go to MIGO – 261 & activate” Propose all items in the settings” then I can post additional component qty .But will this  update the reservation withdrawn quantity.Is this any different from posting unplanned Consumption from transaction MB1A-261.

Can you propose any SAP notes which covers various scenarios related to Goods Issue & Goods Receipt against process orders