Is there any way to map all internal UOMs as Each for External UOM?

Summary:

Is there any way to map all internal UOMs as Each for External UOM?

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For Punchout, when we try to map 'Each' UOM to all of our internal UOMs we are getting error as duplicate value in External UOM column. Or is there any way we can setup default UOM as 'Each' similar to default category?

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