I find that caching of renders brings orders of magnitude higher performance when using the native iOS / macOS canvas, however I get the feeling that there is really a limit to the direct drawing performance possible with a canvas API. I haven’t tried this yet so I’d be happy to be surprised.

Drawing cached renders in quads is how Core Animation works, but they do not scale well. You are ultimately limited by the CPU. Rasterizer enables a fully-animated canvas @ 60fps.