Yep, the font size (and font name) doesn't seem to make any difference.
Ideally, I just want to make all text about 80% of the current size but if I have to put classes in everything then I'll do that. But the PDF Style feature doesn't seem to acknowledge the font size attribute.
I may have now got it working. I put in a color (#000000) and that seems to have kicked it into action! Very strange. And now I've removed the color again it's still working.
I need to add the class to each element but that's OK. There's not much on there as it's all dynamic.