Use the ‘RG Extractor’ plugin by mike@scheduler.ai, then place the Transmit element inside the RG and paste the ‘error preview count per section’ expression in its first field. After that, place the Receive element anywhere outside of the RG, and set its first dataType 1 field to ‘number’.
Now, you can pull the sum of errors from each cell by simply setting the following expression in a text element: ‘Receive A, column 1: sum.’