IMHO the assimilator is nearly worthless. It only tells you that the stator is making some voltage. That doesn't tell you anything concrete about your charging system. If I were concerned about that, I would install any of the available voltmeters or a true charge monitor.
I'm not, so I always install the madass140 oil pressure switch and connect that to the red warning indicator. I very much like to see the red light on while the bike's ignition is on and the bike is not running, and even better that it goes out within a second of starting because I have oil flowing and it is under pressure.