Cloudflare sits in front of both your normal site, and you Super site. If a page is requested underneath the path on which the Super site is connected, Cloudflare fetches the content from the Super site and returns it. Otherwise, it fetches it from your other hosting provider. This is all invisible to the end user.
A Cloudflare Worker does the content fetching and path re-writing. The worker also changes the HTML of the page so that the links point to the correct location and the Super site works correctly running on a path instead of / .
The article is https://coda.io/@matt-varughese/guide-how-to-reverse-proxy-with-cloudflare-workers. The HTML attribute rewriting is based on this: https://developers.cloudflare.com/workers/examples/rewrite-links/.
