Cloudflare Workers are a really great addition to static sites that need just a little wee bit of dynamic content from the backend. It should really be promoted more by create-react-app as a logical extension into back end like dynamically overwriting canonical urls and other meta tags in the static index.html
Redis REST has overhead less than a millisecond compared to Redis TCP. But when EDGE caching is enabled, reads become much faster as expected. Rough numbers we have seen:
REST: ~0.70ms
REST (EDGE cached): ~0.12ms
Note that, EDGE caching is work in progress. It will be publicly available in a few weeks.