by jason » Tue May 05, 2015 1:50 pm
As you may have discovered, docx4j creates a FOP config in org.docx4j.fonts.fop.util.createDefaultConfiguration
There is a property docx4j.fonts.fop.util.FopConfigUtil.substitutions which allows you to specify a resource with contents to be injected into the fonts element.
If your requirements go beyond that, you could modify docx4j's FORendererApacheFOP if you wanted to access/alter that FOP config.