Yes, FFCore can be used with digital web presses. We have customers doing this with both xerox and non-xerox digital presses.
In either case, the digital web press needs the ability to accept a PDF file. If you want a ticketed job you will need to save the PDF and a JDF locally so you can modify the JDF via a script. In this case you will need the digital web press to be able to accept a JDF + a PDF via a hot folder.