I usually ride with my low beams, but have always had bright enough axillary lighting to help make the bike stand out. The headlight modulator is effective and legal, but if riding in a group and not leading, it should be turned off. There are enough bikes, it is certain other drivers are aware of a well formed pack of bikes.
One exception:
When in very slow moving heavy traffic on the freeway, I turn on my high beams in order to alert others on the road that I'm coming trough. Not at a high rate of speed, but gently passing as they sit or move slowly. Most California drivers are accustomed to this practice, but west coast cities are so internationaly transient, I wouldn't count on their knowing California laws or how to drive on an American freeway. But only while lane splitting.