AFAIK There are not many VAD settings on Vapi, maybe only "backgroundDenoisingEnabled". "endpointing" / "confidenceThreshold" is just available for Deepgram. Did you mean other settings?

Vapi mainly supports backgroundDenoisingEnabled and some speech timing settings like stopSpeakingPlan, but it's doesn't have advanced VAD controls like endpointing or confidence thresholds, so tuning these available settings or using external tools is recommended to reduce latency and hearing issues..