Safari / Chrome don't layerize SVG content but Firefox does so you do get hardware-composited async animations when animation the transform property of SVG content in Firefox.
I'd be surprised if any browser is drawing off-screen SVG elements but perhaps some do.
Yeah, maybe not everyone is excited by moving fonts. How about, you couldn't make animated cartoons (which often rely on animating path data) and embed them as <img>s like you can with animated GIFs?
I'd be surprised if any browser is drawing off-screen SVG elements but perhaps some do.