Hi Albert,
The plugin is now configurable : you can decide whether non-mandatory fields are taken in account or not.
All messages are configurable, too.
I'm still confused with how to declare a plugin to Moodle's repository - many weeks after registering it, still no news
But the GitHub version should work (works on a production site using Moodle 3.0).
Any feedback is very appreciated, thanks for your interest.
Greetings,
Mathias