To change other client options, edit the file
-<%=net.i2p.router.startup.ClientAppConfig.configFile(net.i2p.I2PAppContext.getGlobalContext())%>.
+<%=net.i2p.router.startup.ClientAppConfig.configFile(net.i2p.I2PAppContext.getGlobalContext()).getAbsolutePath()%>.
All changes require restart to take effect.