Smart Edge Revalidation , Last-Modified, and Dynamic pages

Assuming I implement If-Modified headers on my website, would Cloudflare’s Smart Edge Revalidation activate and cache pages which currently have cf-cache-status DYNAMIC or do I have to explicitly enable caching (via cache rules) for those dynamic pages first?

Ok so along these lines, I tried an experiment. I enabled Cloudflare caching (via cache rules) on a dynamic page which has If-Modified headers, and then I updated the date on the If-Modified to a newer date and reloaded the page several times. Although it was served from the Cloudflare cache, it never served with the updated If-Modified date/updated version of the page, so it seems that the Cloudflare server couldn’t bother to check my server for the most up-to-date If-Modified header results upon my reloads - hence, it never updated the CF cache with the newer If-Modified date & page. What is the correct way to achieve this?

Bump? Anyone?