Actually, you just need to increase the left margin on this class: ul.level-1
I think you could do it from the extension dialog. Or, you could just go into the css of the vertical menu and create left margin.
Now, if you are trying to layer the flyout on top of the menu, unfortunately my understanding is that this feature cannot be done with the extension at this time. But you can increase the margin so the fly out is flush to the right edge and it will look good.