Both those links describe audio processing on a GPU. Neither of them address (from a quick skim) the roundtrip issue that occurs when doing low latency realtime audio.

Neither applications are designed to run while the GPU maxed out with graphics rendering, are they?

For the unpredictable part of the input, you can't have the best latency and throughput at the same time. If you want realtime in a variable load scenario, you have to cap the GPU usage.

That's how gamers do it when they want the lowest latency possible, anyway. Something like "find the lowest frame rate your game runs on, and cap it to 80% of that".