Agree. More unnecessary bro science. Just flip them and watch magic happen.Switching to 12/12 is stressful enough, why light deprive them and add more stress?
You could take clones of each and put them on 12/12.I have some reg seeds that aren't showing pre flower female hairs, can I leave them in darkness for a few days to find sex or do they need the 12 hours of light to show sex? I want to keep all the plants showing female sex to be isolated from males when I do flip.