Back on blue lights, my principle worry about putting one on my bike is that they're meant to be used in the dark. All drivers can see is the light, not what it's attached to and that's why it provokes the panic response to get out of the way.
I've had near misses several time with people stopping very sharply or pulling into the cycle lane without looking to get out of the way of emergency vehicles that are miles away, more confusion is not what's needed.
Besides, being a stubborn so and so I don't want to change my light set up, I shouldn't have to, people should learn to drive properly.
I personally wouldn't use one, however tempting it might be.