Don't worry about your yields worry about having a healthy plant and the yield will take care of itself. Personally I like to give everything a bit of a rest, my lights, my electric bill, I feel plants do benefit from rest temps can cool off a bit, you will find this is a never ending debate so try it yourself and then switch it up next time. I found plants do grow a bit faster under 24/0 as opposed to 18/6 I kinda go in the middle and do 20/4 for the reasons stated above. Big yields is what your looking for? Then you can veg longer, grow plants know for big yields, have proper lighting and watering/feeding schedule, all that will come to play into your end result not just how many hours of light your plants gets. The guy who grows 24/0 for 3 weeks then flips to 12/12 may be setup to do quick turn-arounds and get less yield but more often. Guy who does 18/6 and vegs for two months and grows bigger plants may have bigger yields less often. Have to find what works well for you and your setup.