SP Page Builder stores page layout and design (colors, padding, backgrounds, etc.) as JSON in the Joomla database. When the page loads, it generates the HTML and inline CSS dynamically. It doesn't create a full static cached page by itself.

Why your changes only appear after clearing Joomla Page Cache:

 The Joomla Page Cache plugin stores the entire rendered HTML (including SPPB inline CSS). So when you edit a page, Joomla is still serving the old cached version until that cache is cleared.

JSpeed or JCH_Optimze it optimizes/compresses CSS/JS files — it does not cache the full HTML.

About the slow first load after clearing cache: That’s normal behavior of full-page caching — the first visitor rebuilds the page.

Speed Up Recommendation:

• Use server-level or CDN caching instead (more efficient and avoids rebuild delays)
• Preload Cache Automatically (e.g. use server cron job, crawler tool or CDN preloader) to keep the cache warm and avoid slow first loads.
• Use PHP 8.4
• Use LiteSpeed Cache Extension or a similar extension that your server supports
• Extra rules for .htaccess file.