Can I cancel a backorder when invoicing in Shipping Data Entry?

SOLVED

It seems like this would be possible, especially since there is an option in Shipping Setup Options to 'allow changes to backordered quantity on line', but I can't seem to find a way to zero the qty backordered column in Shipping Data Entry without it changing the quantity back to ordered-minus-shipped.  Am I missing something?  We just want to be able to cancel our backorders sometimes without having to track down the Sales Order later and delete those lines.  Is this only possible in Invoice Data Entry, and if so, why the aforementioned option?

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