thanks! yes, some of them do, cuz speed is a per-provider capability, not universal. And, you can see it in the gateway code (minimax, hume, xai tts adapters all handle a speed param). that unevenness is actually a routing constraint by itself: "voices that support rate control" narrows the candidate list the same way language or latency does. and agree on the voice modes, the gap between the demo and a dependable agent is exactly why we started this. what are you building with it?