I used to actually T-word him for days on end, which was a lot because for a handful of years I slept 3 to 4 (5 if I was lucky) hours during the day, being up all night. But that was for a reason.
Anyways, no matter when I replied to him, he replied soon after. So either he was asleep exactly when I was, or wasn't it all. So I stopped because I actually started feeling bad, like was I at least partly responsible for keeping him up, and what about the negative health consequences that come with that. I mean, one poke, and it kept him going on for a whole bunch of comments.
During my final college years, I slept minimal hours, and decades later I still can't get normal sleep. And I feel like sludge all day because of it. As you get older, it only gets worse and worse.
But at least now I don't have to feel guilty that I was perhaps contributing to his lack of sleep.