Difference Between configuring Receipt processing time for Procurement(hours) and Receipt processing time for Future Inventory(days)

Problem

Product is designed to handle receipt processing time in different way for in case of these two configuration. Receipt processing time for Procurement(hours) is used to set the time required for receipt processing. while Receipt processing time for Future Inventory(days) is used to provide the time required for processing of received inventory. For example, processing of received inventory may involve unpacking and repacking etc. If the procurement is related to any sales order then the demand will be created based on the ETA of procurement. In that scenario these two values will also be considered for creating future demand date/time. If Receipt processing time for Procurement(hours) will be considered for creating the future demand but Receipt processing time for Future Inventory(days) will not be considered for creating future demand. This may have further impact on demand-supply mapping. For example, in second case, if you get onhand inventory from some other source then that inventory will be considered for fulfilling for this order( because demand is created for current date and Receipt processing time for Future Inventory(days) was not considered for demand creation). However in first case demand will be created for future date (considering the Receipt processing time for Procurement(hours)) and the onhand will not be used for fulfilling this order. So the onhand will be available for sale.