Great flow. Very well thought. 
I wanted to let know my thought because everything can help to find the best for difficult situations.
I use two Chronograph 10 minute timers.
Brightness is measured by Fibaro sensor which is outside just above the two screens I have.
If brightness is enough counter starts. If the brightness goes under setup value (cloud) it stops the timer and starts the other one. If it reach the 10 minutes the screens go up. If the brightness is constantly 10 minutes below setup it lowers the screens.
The flows are activated and deactivated between a time window to only use memory when
