In this post
http://forum.eyesweb.org/viewtopic.php?f=34&t=154&p=318#p318 You can find a way to startup a display in fullscreen mode.
Export the "Fullscreen monitor index" parameter of Display block to be set fullscreen when the patch is started.
Then attach the output of one "ConstantGenerator - int" block to this exported parameter and write into the "ConstantGenerator - int" block the number of screen where You want to anchor the fullscreen Display (0 is primari, 1 is secondary, ...).
Feel free to make any other questions,
bye