Preview cache expiration limits affecting StackBlitz live updates

When editing a file in a StackBlitz project, the preview iframe may continue to serve a previously built version until the CDN cache expires or is purged. The platform states that assets are cached for a short period, but the exact time‑to‑live is not published and could differ between free and paid tiers. Understanding this limit helps determine whether a manual preview refresh or a cache‑busting query parameter is required to see immediate changes.

What is the typical cache TTL for preview assets on StackBlitz, and does it vary by account type? Does the built-in "Refresh Preview" button guarantee a cache-bypass, or can stale content still appear after using it? Are there any documented limits on how often the cache can be purged programmatically?