Are you trying to achieve something like this:
This is handling packs of objects. The actual pivot table is aggregating the lengths, but in the microflow that builds the transient data for the pivot table, I create single records for each pack with the shipping reference, total pieces and total volume (As a string with the units). The XAxis is sorted by an ID variable so I can get it in the required order, but otherwise it all works how you would want.
Previously I concatenated all the info into the reference as your other suggestion goes but it wasn’t nearly as neat or user friendly.
HTH,
Dom