here a link to the information on the reg that supersedes state statues. I carry this with me, and have never been stopped on this issue.
motorcycle headlight modulator regulations - webbikeworld
the thing that can cause you a ticket is if the modulator operates once it gets dark. Mine both have a photo sensor built in that stops the modulation once daylight gets reduced to a certain level.
I consider using this just as ethical as my right to not be hit by someone who mind is not focused on driving. While one can say it draws the drivers attention, i consider it no different from daylight running lights which became standard on many automobiles years ago. The idea of those was to catch the attention of the drivers coming in an opposite direction.
Problem is with so many vehicles with headlights on, try distinguishing a single beam headlamp from the traffic. Single beams definitely do not stand out in the daylight anymore. In many cases when we go out for group rides, folks prefer me to be one of the first two in the group because of my modulating headlight.
The other thing i do from a courtesy standpoint is that when i am doing urban riding and am stopped for a traffic light or in heavy same direction traffic, i disable the modulation to not annoy the driver in front of me. However in the case where the sun is at my back and where there is a lot of traffic entering the road or opposite direction turning traffic, i will keep the modulator on.
Jack