Quoted from OLDPINGUY:Manual blinking control proto types are in the works.....For those that want absolute control and speed of blinking....it is suppose to take any bulb, not a blinking bulb, and create an external blinking rate thats adjustable....Awaiting the prototype in 6.3V...12V tested OK, just trying to shrink down.
Having Fast and Slow is a great choice, clean and easy....I have not yet seen these sync.....but anythings possible.
Art, thanks for the update and great line of Bulbs. Hope to see ya at SFGE