If you install a modulator, I encourage you to carry some tape to cover the ambient light sensor, or include a switch to disable it. This is for use when you are riding in a pack. Modulators are irritating in a pack, unless you are riding point, then by all means, leave the modulator on.
I'm just sayin'...
Enjoy,
Rich P
Let me play Devil's advocate and throw a question out there. At least in the USA, what is the universally accepted signal for telling another driver it's OK to turn in front of you? Answer - you flash your high beams!
Installed one a few years back on the high beam & only put in on as needed when i feel the driver is distracted ie intersections .