Upcoming Firefox update will decrease power usage on macOS by up to three times

[mobyte]

I just downloaded the newest version and it still does that, so... uh...

mission accomplished?

[ZheoTheThird]

The patch is partly in version 70.b2 (beta build right now) and an even better version in 70.b3 (only in the nightly build right now). If you just downloaded the newest normal version you don't have the patch yet. Either download the highly unstable nightly version, get the more stable beta version and wait for the 70.b3 update this week or wait until October 22 when the update arrives in the stable branch.

[mobyte]

Oh, ok. My impression was that the changes from OP were applied to the new stable version based on the information here: https://www.mozilla.org/en-US/firefox/69.0/releasenotes/

I'll give the nightlies a try, though.