My last 3 grows have been autos,I think it depends on the strain and not how long you run the lights ,if it’s a strong strain it will grow,my last grow I had 2 gorilla glue grow 6ft tall and 2 other strain of gorilla glue grow 2 ft high ,sour kush plant out grew my tent,almost 7ft tall and I was running 12-12 lights
That’s my thoughts on it,I could be wrong won’t be the first time lol