Report to display excess available inventory

As a clothing company, we regularly take pre-sales 6+ months in advance for future delivery. When then create purchase orders and begin production. During that time, we also receive replenishment orders that use our current inventory on hand. We have to be diligent to ensure that we don't accidentally utilize inventory on hand that will be used for those future orders. I'm exploring the order management dashboard and have found it useful. However, i need to be able to generate a report of non-allocated/committed inventory to know what excess we have for that future date.

I'm trying to modify the inventory backorder report to include "on order," however when i do so, it appears it shows up on a transaction basis rather than a total basis. Screenshot attached. Is there a way to get that field to show up in the summary column so i can know that ACC-H01 has 499 ordered, 490 backordered, 1000 on order, so i would have 510 units to pre-sell to other customers?