That's a great question! My first implementation was interruption on voice activity after echo cancellation. It still had way too many false positives. I changed it to incoming realtime transcription as a trigger. That adds a bit of latency but that gets compensated by way better accuracy.

Edit: just realized the irony but it's really a good question lol

That answer is even more than I could have hoped for. I worried doing that might be too slow. I wonder if it could be improved (without breaking something else) to "know" when to continue based on what it heard (active listening), maybe after a small pause. I'd put up with a chance of it continuing when I don't want it to as long as "Stop" would always work as a final fallback.

Also, it took me longer than I care to admit to get your irony reference. Well done.

Edit: Just to expand on that in case it was not clear, this would be the ideal case I think:

LLM: You're going to want to start by installing XYZ, then you

Human: Ahh, right

LLM: Slight pause, makes sure that there is nothing more and checks if the reply is a follow up question/response or just active listening

LLM: ...Then you will want to...

For at least 12 years it's been used as filler. Pay attention to interviews of any sort. Half the time it's in response to an obviously scripted question.