I cannot speak to the specifics of XFRX, but I have tried a variety of ways to print out VFP Report Forms reports to PDF files.
I ended up not using a 'tool' such as XFRX, but instead used a PDF 'printer' and merely output the report to that 'printer'. In my particular situation I found the BullZip PDF 'printer' worked the way I needed for my clients.
But in general, the manner in which any PDF 'converter' turns documents out from format A to format B (PDF) is due to how they handle things internally. Those products may or may not allow you to manipulate various parameters.
Good Luck,
JRB-Bldr