"Works" with the android stock browser, however there the controls stay in the way. Same for Chrome. Does not work with opera mobile.

Much to my annoyance. I desire to disable all autoplay of all inline videos across all browsers on my phone. Quite difficult to achieve.

I think this should definitely be an option. This is a really personal preference and there is no reason you should suffer through autoplay videos if you don't want to.

I would want it on, at least for some sites, like Gyfcat and Imgur because otherwise my phone slows down to a crawl, trying to load and render a GIF.