In Firefox version 59.0.2 on a Core i7 6xxx series with the latest nVidia graphics card drivers, when on battery power only, my two-finger touchpad scrolling experience in Firefox is terrible. When I scroll with two fingers and hold (i.e. not flick), scrolling by half a screen up or down, the scroll starts right away, but takes several seconds to get there. Here's an example. In this Gfy, I gestured fast and cleanly, in a split second, but it took several seconds to be done scrolling. The two finger gesture was in one motion, but the scrolling window seemed to scroll slow and medium speed and then slow again.
The problem isn't so much lag per se--it starts scrolling immediately; nor is it starving for CPU or resources. It seems instead that there is something programmatic keeping it from scrolling faster or "with more FPS".
Other Windows apps seem to scroll with the gesture just fine.
How can I fix Firefox's slow-responding two-finger touchpad scroll when not plugged in to AC power?
An internet search reveals a ton of dart-throwing ideas to fix similar (but not exact issues) I tried turning off smooth scrolling and pixel scrolling in about:config; that didn't help. I'm sure that the CPU behavior is different under battery power, but I don't see a setting "make touchpad scroll slow in Firefox" in Windows Power Options. Any ideas?