I know people have said they put colored flashers behind Ra, so I was going to try it but only had white bayonet on hand. So I put in the white LED flashers I had in the 4 flasher spots, but they immediately started flashing. Not strobing/flickering... full power flashing the whole time in attract mode until I started a game. I couldn't stand it doing that all the time, so went back to the incandescent flashers.
You are right, there are only 9 controlled lamps... I forgot the middle one just has one. I tried incandescent, frosted cool/warm bullet LED, colored convex LED, 2-LED faceted, 5-LED flat top, and basically everything I had on hand that was a bayonet base. They all looked good/normal in the standard sockets but sad/weak and barely on in the controlled. Even the incandescent looked like it was a faint orange glow instead of the warm light they normally put out. I ended up using the cool bullets since they had the most output of the group, which is why I had to use so many of the Op Max because I only had 25 total on hand. (I think my eyes are still screwed up and seeing spots from last night. Dang those things are bright while looking straight at them.)