If your site is completely static like a blog, maybe the best way is to use a static site generator like hugo or jekyll. There is no need to re-invent the wheel. However, If your site is dynamic but with a sizable portion in static content, it does make sense.
In the static site generator world, they give up on the digest idea. However, static host like Netlify and Vercel maintains http etag for each file automatically to solve the cache invalidation problem. Maybe that’s the way to go. Can Nginx generate/maintain etag? Can Cowboy generate/maintain etag? If so, do we really need digests?