Yes you use the pdf export...but isolating the die line was the bad part unless you messed around in acrobat using actions or re-reipped die line only file. But the layering function in xmf makes it work well...as long as you set the pdf up correctly beforehand.
From the 'workflow items' in XMF add the PDF export task to your workflow between the imposition and press tasks. Select the task to configure the parameters. Recommend exporting PDFs as SHEET size as opposed to PLATE size. See attached XMF workflow screenshot.
NB. Easiest to use a separate PDF source file of only the Dieline / Cutting forme content than trying to remove all the cmyk artwork objects post export.