How do I get the redlined row ID from a BOM?

There's a simple way to get the BOM ID field from a BOM row, just by returning IRow.getRowId().  Unfortunately, this does not return the new BOM ID when a row is redline changed (new item, change of quantity, etc.)  I can see a m_redlinedRowId associated with the instance of IRow, but it's always null, almost like the developers wanted to add it, but it never was completed.  Is there any way to get this?