Service worker updated

I currently have a service worker implemented in my web app. On installation of the service worker, an array of static assets are cached – (html, css, images, js) Once installation completes the service worker will cache dynamic assets (network requests, cdn, fetch etc.!) When the version number of the service worker changes, the old cache is deleted, old service worker is unregistered and the new cache and service worker are installed and registered. To this point everything works fine The issues I am facing: 1. PHP files are being cached and I would like to avoid this. 2. Develop a caching strategy for using the cache first, then network - except for files that get updated constantly with "live" data - 3. Delete old files when no longer required If the freelancer prefers to use workbox (it is in the development roadmap) then this would be an ideal situation -