Which Light Cycle for Plants in Different Stages Sharing Space?

DLI is what matters.. hopefully you are giving as much as your local variables allow over 12 h. but if not, definitely increase hours of operation for autoflowers, as you do not need to change that to initiate flower. Read the wiki on daily light integral and understand the gist of it. if you want a certain plant to get less light for whatever reason - i won't get into whether or not that is a positive or not becuase it's at best a maybe - move it to the corner or otherwise reduce the light it receives in a physical way... keep the others in the stronger areas of light. You can also use pot elevators for the ones that need more (do adjust lights properly for their new height) and that in turn will give less to the relatively shorter plants.

PS : You also need to review your feeding schedule, and lower the humidity in your tent if it’s over 90%, or mold will start to appear

hey 👋 If I read your diary correctly, all your plants are autos; so switch to 18/6 without delay, and keep that schedule until harvest.