Let me clarify.

I cannot definitively answer the question without involving R&D who are current;y involved finishing other projects. We have never had anyone bring "fantastic costs" to our attention, and indeed, our costing of inventory does not slavishly follow ACCPAC where we disagree with their computations.

Certainly you could identify items with non-zero FIFO/LIFO buckets that net to zero in GridView with a couple of minutes work. I created a View and have uploaded it here.