For the man who lies down at a reasonable time and then loses two hours to his phone, his thoughts, or whatever his brain decides urgently needs solving at 11:30pm.
Sleep is ADHD infrastructure. Focus, mood, impulse control, and medication response all run worse on bad sleep. This gives the wind-down the same structure the rest of the day gets.
Use it when the night is becoming stimulation, rumination, or avoidance.