I’d extend check-meta to check the body too: the expected H1, a route-specific paragraph and the main links. The JSON-LD element can appear before async content has finished loading, so it’s possible to save a snapshot with a complete head and a loading state in the body.

If the page has async content, I’d wait for a signal from that content before saving it, then check the deployed URL as well as the file in dist.

I’m building Prerender Buddy, so this is close to what I work on. The check that matters here is what the URL actually returns.