Meanwhile, my Unihertz Titan (with a Mediatek Helio P60) handles it pretty well in Firefox Nightly (a couple stutters at the beginning and in the middle, but ot

Meanwhile, my Unihertz Titan (with a Mediatek Helio P60) handles it pretty well in Firefox Nightly (a couple stutters at the beginning and in the middle, but otherwise smooth) - so the operating system and/or browser could be factors as well.