I use a dual harness modulator on my 1500 from signal dynamics, it is great with a lot of features. it can be tied into your horn so that it will modulate faster when you hit it. You can also adjust the modulating speed from just turning the high/low beam up and down 2 times really fast. The only bad thing about it is it cant be hooked up to LED's.
If you want LED's I would recommend Kriss.com, they have one that can modulate certain LEDs.
I know in MD, it is illegal to use a modulator on fog lights or driving lights, it must be the headlight. The law might have changed since I got my MC license in 2015, but I doubt.
I HIGHLY recommend a good flasher. Most people I have encountered up and down the east coast think it is a cop MC and give me distance.
2000 Goldwing Special Edition, starting with 23k miles
Ham Radio Extra Class-KB3WEY
8 lives left