> We save 7TB per mo egress because of Cloudflare's free cache (through Workers) and pay nothing for it.

That's huge, Could you explain a bit more on how you achieve that? I've been exploring Cloudflare cache, AFAIK for anything not cached by default you need a special page rule e.g. for .html, I tried a wildcard domain.com/* and it doesn't seem to make any difference. Are you using workers to cache specific file types?