First thank you for this very useful plugin. I have tested others doing the same thing but yours is the best. It works without any warnings and does not create extra tables like other plugins.
I just wanted to point out two things.
1. There are some useless files in you zip package (.gitignore and assets/*). You should set a .gitattributes file to prevent them from archiving.
2. I am using a French site, and when I activate the plugin, the English language is not displayed in the dropdown. To display English, I should first select «French» even if I am already in French. After that, it works perfectly.