So I had a live-in tenant with this ability. Getting woken up an hour after I went to bed and then again an hour before my alarm by the normal activities of an awake person took its toll on my health and we had to part ways. I had lived with many people before that.

I do, and I still wish for more than 24 hours to a day, because of how much work I need to get done every day. I typically get 3-4 hours, with the sweet spot at about 3.5 hours. And I've been doing that since I was about 14. Sometimes I sleep for 6 hours, but that's very rare. Sleeping for 8 hours is out of the question, because there's no way my eyes will remain closed for that long. And I've only used an alarm once, back when I was in high school.

Once I wake up, that's it, until it's time to call it a day again. And I don't drink coffee or take any other stimulant. I only get tired or fall asleep during the day if I eat something that has a high Glycemic Index or too much of something that has a high Glycemic Load.

As someone who does I promise you: no you don't

I mean as long as you can keep healthy as the guys in that article, why not?

I can already imagine the beautiful life I'm going to have if I only need to sleep 4-5 hours. Getting up at 4:30AM, brew some coffee and make breakfast, sit down at 5:00AM and code for like 3 hours. Then I'd workout a bit, take a shower and go to work.

My job is pretty demanding at the moment so I'd rather do the more interesting stuffs in the morning instead of after work (I usually arrive at home around 7pm so it's a bit tough).

Why not?

Seems to me that having a physiological pattern which forces you outside the normal rhythm of society could be detrimental to one’s mental health (pure conjecture).

Or beneficial! Depends on the context really.

For one, because your time is of lower quality (without enough sleep).

Second, because while it might be more in a day, it's less overall (you'll die younger).