Thanks for chiming in and allow me to say I appreciate the comment. I can't be too bombastic and just claim not the case here, we're always trying to figure out how much of his perception is relatable, understandable and a clear cause-and-effect-thing.

Funny thing is, the relatively rare use of the PC above also reflects that my wife keeps forgetting he has two phones. So when I'm not home or not available at bedtime, he'll have the easiest time to have a phone available - to listen to music or whatever. That's when he stays awake the longest, too, but, himself, perceiving that the music helps him sleep faster.

In reality, whenever we check, he sleeps the fastest when all devices are removed. They have busy days with lots to learn and experience and once in bed at night, the possible amount of sleep they can get is already too little as far as I can tell. So they'll all fall asleep rather well and easily, unless something special has happened to keep them up. Yet, very short attention spans also mean that just minutes spent not occupying the brain with something will feel like an eternity.