Light intensity is the same, but I found that half strength nutrients was plenty strong enough for autos.
Never grow 24/0, all plants, cannabis included, NEED sleep to finish their photosynthesis cycle and for a correctly functioning metabolism.
A plant with an incorrectly functioning metaboilsm will never produce healthy cannabinoids.
24/0 could only be recommended by people who do not understand photosynthesis or how plants function.
18/6 is optimum for autos, from day one until harvest.