This panel is a simulator for runtime rendering states only. Real defaults live in apps/astro-site/src/config/bookbat-client.config.ts and are passed from apps/astro-site/src/pages/index.astro through <BookBatClient config={bookBatClientConfig} />. If you reuse this component in another Astro site, import defaultBookBatClientConfig, override only what you need, and pass config; omitted fields automatically fall back to built-in defaults (header/footer on, export on with all formats, load off, styled mode on).