Think of an auto like a cancer patient that has been told they have 90 days to live ... And the only thing on your auto's bucket list is flowering ... no matter what you do, that plant is going to switch between veg and flower on a schedule that allows it to knock out that one bucket list goal. A rich auto will live out it's 90 days in luxury with endless light which will result in maximum yield... a poor auto will scrape by with whatever light it can get, but still achieve it's goal and flower; however, the end result will not be optimum. Rich or poor, the 90 day clock is set and won't change (not saying your specific auto has a 90 day clock, obviously).
So, you can absolutely give them only 11 hours of light, just don't expect great yields.. I don't know what autos you are growing, but you should adjust your expectations to a low yield in 11 hours of light. I'd be pretty surprised if you were able to pull an oz. under those conditions. Maybe a half oz?