The framing in this thread is full-duplex vs composable pipeline, but I think the real architecture is both running simultaneously — and this library is already halfway there.

The fact that qwen3-asr-swift bundles ASR, TTS, and PersonaPlex in one Swift package means you already have all the pieces. PersonaPlex handles the "mouth" — low-latency backchanneling, natural turn-taking, filler responses at RTF 0.87. Meanwhile a separate LLM with tool calling operates as the "brain", and when it returns a result you can fall back to the ASR+LLM+TTS path for the factual answer. taf2's fork (running a parallel LLM to infer when to call tools) already demonstrates this pattern. It's basically how humans work — we say "hmm, let me think about that" while our brain is actually retrieving the answer. We don't go silent for 2 seconds.

The hard unsolved part is the orchestration between the two. When does the brain override the mouth? How do you prevent PersonaPlex from confidently answering something the reasoning model hasn't verified? How do you handle the moment a tool result contradicts what the fast model already started saying?