I personally am finding that autos will grow anywhere in any light schedule...….20/4...…...18/6...…..16/8...….12/12.....and even 11/13. I usually have a least one running at all times, generally two. And wherever I have an open space that's where they are grown. Currently I have one of my auto crosses growing inside. It's been in my homemade vegging box under 18/6 lighting where it lived until that box was overfilled with photo plants that weren't ready for the flowering tent yet. BUT I had a hole in my flowering tent, so I made space in the vegging box by moving that flowering auto and putting it into the flowering tent under 12/12 lighting. It lived there for about 3 weeks at which time one of the vegging photo plants was now ready for the flowering tent. So I removed the autoflowering plant and put the photo plant into the flowering tent. There was still no room for the auto in the homemade box so I stuck it in my slow grow small vegging tent with a Black Cherry Punch photo plant. This tent is lit with a small LED light set up on a 16/8 lighting schedule. She will likely finish in there as she's getting close.
I think the point I'm trying to make is that auto flowering plants are a tremendous aid in keeping more of a perpetual grow. You can start one every 2 weeks, do minimal training to it, grow it wherever you can squeeze it in, and every two weeks harvest a decent amount of good quality buds all with little aggravation.
They allow us to concentrate on our photoperiod plants, seed making, or whatever and they keep plugging along in the background making buds. I am expecting 21+ grams of dried buds from the Canuk Quarter Pounder X Fast Buds Gorilla Glue I am running right now. So sure, why not have a few running at all times??