Firefox useful settings

You can found hidden config on about:config

• layers.acceleration.force-enabled set to true, if your screen flickering when you scrolling or watching videos
• layout.css.devPixelsPerPx can control browser scale with this param. Very useful for users which have HiDPI screens!

Update 19.06.20/20.06.20:

• browser.display.focus_ring_width set to 0 to remove ugly dotted borders around the links
• gfx.webrender.all set to true to enable WebRender
• browser.tabs.tabMinWidth reduce to fit more tabs (like in Chromium)