Unfortunatly I can't be to helpfull either but I remember on O.G. some people were getting 5 on/offs over a 7 day week. I think they were getting more yield off the plants but it took upto a month longer to flower them. I can't remember if the incresed yield would be worth the wait.
It was more about giving more light time like 18/12 but as perp said i think 12/6 (or 6/12) would decrese yeild but would bring harvest date forward.