Brake light modulators are many decades old, generally illegal, and therefore aftermarket modifications. The ones that light up like a Christmas tree for feathering the brakes are obnoxious (other than for motorcycles, perhaps), but I'm totally on board with this being standard for ABS situations and similar.
I heard more than a decade ago that Mercedes designed that system but could not pass regulations back then. Plenty of cars do it today so that must have changed.
