In the harness drawing if you target the line underneath the loom you should be able to see the calculated length vesys sees of the bundle. You said you had a dozen wires and then you said you ran your calculation running two. I don't see how 1.68 * 1.3 =16.48 , Make sure you run the calculate node bundle size first before doing insulation calculations as well.
I wish the calculation would just be one button and do everything at once in the proper order.
Seeing your numbers on the outside diameter on the multicore and other wires would also be beneficial.