Thread wake-ups may reveal issues in scheduling, especially timer related scheduling.
So, would be be good to have some analysis on how much and when Gecko does wake-ups.
What kind of analysis is still TBD.
Somebody was looking at this recently and Firefox was doing ~3x more wakeups than Edge. I agree this would be good to look at in some more detail.
FWIW, I'm looking into some of this. And we've already fixed some timer cases related to GC handling.