RMA and Purchasing Unit of Measure

We create an RMA with one line as CRP with no OM generated.  This is because RMA is unable to manage SI - Intercompany documents.

Separately we create an REC line in the same RMA for the same item and lot number.

When we create the REC line, we enter the item, lot, and quantity, but there is nowhere to add the Unit of Measure.

When the OM is generated, the quantity from the OM is assumed to be in primary units and converted to the Purchasing Unit of Measure, but the OM is presented in the purchasing unit of measure