I don't have the timings right now but you can go significantly below 10ms.

There's a tradeoff between quality and encoding time - for example, if you want your motion vector reference to go back 4 frames, instead of 2, then the encoder will take longer to run, and you get better quality at no extra bitrate, but more runtime.

If your key to-screen latency has an irreducible 50-60ms part of rendering, processing, data transfer, decoding and display, then the extra 10ms is just 15% more latency, but you have to find the correct tradeoff for yourself.