Ahoi Captain✌️,
my suggestion would be to change your light cycle to 18/6. I have to say I'm no big fan of 20/4, or 24/0. I think the damsel would be always stressed If there's no, or less time to recover.
Depending what you wanna do with your photoperiodic Señorita. If you keep her in veg for 6-8 weeks you could finish your Automatic and then switch to bloom for the photo- damsel.
I did it exactly this way in my actual run. I had a Lowryder Auto in the Box and two photoperiodic plants. Harvested Lowryder beginning this week.
Hope this helps a bit, If you wanna talk further just throw me a PM!
Have a good one, cheerz...
OimRausch