Wow that is great to here. I would love to help test. I currently have a 4 screen setup that displays a main game window, a marquee monitor, a smaller monitor that displays the control panel image and the fourth monitor provides general info, graphic ads or the RL pause screen. At one point I had ledblinky implemented but it required too much baby sitting to keep working, so I would rather just see a control panel image.
I think a comprehensive solution would allow for additional displays on different monitors or on different regions of the main screen. So, for example, I might have a single large screen and I want a bezel to show the arcade cab bezel art and/or an image of the CP, or whatever. Plugins to various front end would be a plus. Personally I use RL plus Hypermarquee to accomplish this now on my Mame setup; and PinballX to do it on the pinball cab. The brings up the other issue, that the added screen (or screen regions) need to be able to render animation (the backglass screen of a pinball cabinet is commonly animated).