So that video was made about 7 years ago which means 2016 but the MoRTH released a Gazeted order in January, 2016(which is attached below) basically saying every 2 wheeler will have it’s headlamps on as long as the engine is running. In Ather’s case the “engine” is the motor so basically they decided to have the headlamp running always since there’s no separate 12V battery and everything is run off the main battery through different voltage converters.
Having the lights off will not save a significant enough amount of power to give you any extra range.
I think you have posted this same question in one of the channels before, right? If yes, then you got the same reply as above. How much power do you think having the lights off would save? Care to elaborate on that claim?