ATP Not Respecting Discrete Job Supply and Completion Subinventory Statuses

It appears that ATP considers all discrete job material requirements as demand regardless of whether the requirement lines have a supply subinventory that is atpable or not.  Likewise, ATP includes all discrete job scheduled completions as supply regardless of whether a discrete job's completion subinventory is atpable or not.  This can be confirmed by digging into ATP's Supply/Demand or looking at the Collected Data Supply/Demand.

Interestingly the Inventory Item Supply/Demand and Discrete Job's Check ATP functions do respect the Supply and Completion Subinventories.

Is this expected functionality?  How can I get ATP to respect those subinventories?

Thanks,