Standalone Viewer - launch to fullscreen

Hi
can't seem to find an option or way to launch the Standalone Viewer to fullscreen (by default)
...seems like it should be simple - maybe I've missed something obvious?

also, is there any way to assign the fullscreen command ('Show VIEWERCMD=fullscreen')
to a mouse double-click on the current image in Standalone Viewer (not a middle button click)

cheers

The option you're looking for is Preferences / Viewer / Appearance / Auto-size viewer window / Full screen.

On the Preferences / Viewer / Mouse Buttons page there's a Toggle Full Screen mode option in the drop-down that you can assign to any of the supported button actions.