$FFwfDoc.documentSequenceNumber$ may be the FFCore variable you are looking for.
The forum helped a lot with the former problems in generating barcode marks for sewing workflows. Anything would be fine with the function, but we want climb the next step of it.
There should be 2 templates on one printsheet. The first one is starting with page one on the sheet and the second templates is numbered from the back.
For doing so, i doubled the printfile with splitting all pages into two lanes. In these lanes the sewing templates are working fine. But the variable $FFwfJob.documentGroupCount$ puts out the number "2" at any constellation. It seems to be, that the first split is responsible for the number. Is there another variable for counting the number of segments? Or any other trick to "reset" the variable within the workflow?
https://forum.support.xerox.com/t5/FreeFlow-Core/Barcode-generation-for-sewing-workflow/m-p/236596
https://forum.support.xerox.com/t5/FreeFlow-Core/Imposition-for-sewing-machine/m-p/234758