Firefox and youtube playback

[Luke]

For starters you may want to make sure to prevent pinch-to-zoom behaviour by setting:
zoom.maxPercent to 100
zoom.minPercent to 100

If you want to retain the ability to zoom with the ctrl and +/- buttons, you can alter the mousewheel.with_control.action setting instead. From Mozilla's wiki:

Customizing default action of "wheel" event. The value 0 means "Do nothing", 1 means "Scroll contents", 2 means "Go back or forward in the history", 3 means "Zoom in or out the contents".

Excellent. As a side note, how is the firefox experience for you ? despite so many people saying that firefox is dead slow compared to chromium, I find that with these tweaks its on par with chromium in the Mate desktop (installed on eMMC).