Change PDF style

Hello, can I change the PDF-style settings somehow? I see some xml and xsl files in the content folder, but not sure if that change something at all. that would be great to have them files outside the program to justify the parameters as long they are not in the software itself. The same for the chart-picture.

There is a PDF-Theme Sortavala - are there more themes to install? I wanted to make the chart list more readable by changing the font size.

GanttProject 3.3 allows for changing the base font size in PDF export.