I had a somewhat crazy idea. What if we were to have just the one button in the header, and have that open a big popup akin to the keyboard shortcuts popup? It would be shown to logged in and not logged in users.
That could give us plenty of space, all in one place, to:
- explain that the site is automatically translated, how it works
- provide a link to more information about automatic translation or to give feedback to site owners about it
- allow the user to specify their preferred interface language
- allow the user to see a big list of languages currently translated on the site, with tickboxes indicating which they want translated (default selected, with ability toggle them all on/off). The list could also indicate how many topics from that language have been translated.