Thanks @arunbasillal – that makes good sense. Thank-you.
So I went for your second option and set an offline page (in SuperPWA > Settings) that doesn’t have relative links – https://stuco.hopto.org/notcached/. I made a new page telling the user what had happened. It all works well apart from one thing. I put an image on this page but the image seems NOT to get cached if I use a device that hasn’t visited that page whilst it has been online. This would be the case for all devices apart from my development machine, because, of course, the user should never get to that page unless the app is offline.
I have also changed my ‘Application Short Name’, but that doesn’t seem to be getting updated. I may have a caching problem. I’m using Windows 10 / Chrome to develop on and an Android 6.0 (LG G3) phone / Chrome to test on. I’ve tried clearing Chrome cache and uninstalling and reinstalling the PWA on Android, but the old ‘Wiswo Courses’ ‘Application Short Name’ persists. New short name is ‘Wiswo Pali’.
Many thanks for your help.
