I hope not. Partly because I'd like to learn how to do what they do.
Oh well.
There is almost certainly some trade-off, otherwise the gene would probably be heavily selected for.
The trade off is that being asleep for shorter and awake for longer exposes you to, let's say, 3 hours of extra risk daily. Plenty of ways to die in that timespan, when historically your tribe was still sleeping. I think that may be a major tradeoff
Not really. Being asleep is actually quite dangerous in nature, and you are quite safe awake in shelter.