If I serve cloudflare images on my non-cloudflare hosted webpage, would the visitors still occasionally see the injected DDoS protection “checking your browser before accessing” page or would the images just fail to load then? Or is that browser checking disabled if just loading images?

That’s one reason why I haven’t checked out Cloudflare Pages, my (already statically hosted) website will unlikely be DDoSed and I wouldn’t want to impact user experience by adding random browser checks…