[0] https://www.dell.com/community/XPS/FAQ-Modern-Standby/td-p/7...
Previous HN discussion: https://news.ycombinator.com/item?id=28639952
Hibernate S4 itself is fine, except the risk of physically triggering wakeup.
I'm not sure about linux or Mac though
Has helped me identify flaky input peripherals or timers many times. Worst was an HP laptop with a wonky touch bar for media controls, that would frequently ghost press and wake the computer, even when in hibernate and with the lid closed.
Ended up being a security risk at our company because someone in marketing didn’t know this and made a full screen video. Well, cleaning staff came in and almost all our PCs were on because lots of people use the company website.
Fixed that nonsense right away.