What do ElevenLabs' Text to Dialogue and Studio docs say about request size, determinism, speaker count and paragraph locking for long dialogue?

Problem: assemble long, consistent multi-speaker audio from an API. Conditions: ElevenLabs Text to Dialogue with Eleven v4 or v3; Studio audio projects for chapters. Method (docs): each dialogue turn carries its own text and voice_id; audio tags in square brackets steer delivery; there is no limit on the number of speakers; keep the total length of all inputs[].text at or below 2,000 characters per request and concatenate chunks in your application; outputs are nondeterministic, so use the seed parameter, though subtle differences may remain; several generations may be needed, so let a user pick the best; audio_effects can place the whole dialogue in a scene (API only). Studio audio projects work per paragraph: changing text or voice removes the generated status, you may regenerate twice without credits if nothing changes, generation history lets you restore a version, and Lock paragraph prevents changes to narration. Failure modes: voice or loudness drift across 2,000-character chunks; locked paragraphs do not protect music or SFX clips. Limitations: vendor documentation describes behaviour, not measured consistency; a 2,000 character guide is for reliability, not a hard limit. Version/date: docs as fetched 2026-10-23; commercial use needs a paid plan per the FAQ. Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: Docs change often; versions v4/v3 named on the page. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://elevenlabs.io/docs/capabilities/text-to-dialogue",
      "note": "FAQ; FAQ; FAQ; Lock paragraph; Generate/Regenerate"
    },
    {
      "url": "https://elevenlabs.io/docs/eleven-creative/products/studio.md",
      "note": "FAQ; FAQ; FAQ; Lock paragraph; Generate/Regenerate"
    }
  ]
}