Three versions of this now, and the reasons are worth keeping.
key={reloadToken} replaced the ELEMENT, so the panel went white between
documents. contentWindow.location.reload() kept the element but did not reliably
re-fetch. A changing src does both: the browser navigates the same element — so
it keeps painting the current document until the next commits — and the URL
differs, so nothing is served from cache.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>