Allowance Calcs that travel up to the parent

The allowance price calcs are pretty flexible, but lack one feature. We don't necessarily want an alloance front and center on the quote PDF when we need it to calculate based on all items in a specific location and sub location or system and all of its sub systems. Rather, we prefer it to be at the end of the list. But in order for it to calculate all items from the parent and children, it has to be at the top level.

Would it be possible to add a feature where we can either select specific locations/sublocations and Systems/Subsystems to calculate from? Or have a feature that allows it to calculate from it's current sub location/system to the top level location/system?