Howard Miller

That sounds wrong. An 11KB backup is tiny and should take no time at all. First thing... how often is your cron setup set to run?

If every second (as recommended) then what else is happening with your tasks that is preventing the restore from running?

If you haven't, you should definitely read Cron. There's lots of useful information. The tasks subsystem has a few settings you can 'tune' as well.

...and me. I'm terrified of submodules.

"An external system" ??

I suppose it depends. Moodle has the concept of course (or activity) "completion". You (or someone) can write a plugin that can trap that and trigger your "external system". But, of course, the devil is all in the detail.

The data is in the database, so you should be safe. Even if you upgrade without the plugins.

Does this help? https://moodle.org/plugins/tool_upgradecopy

All browsers on iOS are Apple WebKit. They're all using the same browser engine, same bugs.