This week, I got an idea on how to control the print dialog in FileMaker. So we now can control there a few features like selecting which printer should print. And we can define in a script that we like to print to PDF and provide the destination path. Also we can automatically dismiss the dialog with OK so the user doesn't see it.
And voila we have on Mac another way to generate a PDF from a layout without user interaction
Comes soon with 3.5pr5!