In my experience autoflowers do best under 24 hours, but only if it is a good and stable strain.
I know that they are C3 plants and they produce energy only when the light is shining so theoretically you need to supply as much light as possible, but in practice there are many more factors like the electricity price, bulb/ballast life expectancy, heat signature and strain stability. All or non of them can influence growers decision for the best light cycle.
I know that they are C3 plants and they produce energy only when the light is shining so theoretically you need to supply as much light as possible, but in practice there are many more factors like the electricity price, bulb/ballast life expectancy, heat signature and strain stability. All or non of them can influence growers decision for the best light cycle.