Yes, my issue with these types of 'services' always is that it only 'emulates' the screen resolution. They might as well just be iframes locked to specific reso

Yes, my issue with these types of 'services' always is that it only 'emulates' the screen resolution. They might as well just be iframes locked to specific resolutions; the result is that it's still my own browser doing the rendering. What I want is some kind of reverse-polyfill that accurately reflects the rendering capabilities.