On French Wikipedia, in the editing mode (logged-in or logged-out), the language switching button is grayed out, and users aren't able to use it.
(Check how it's working now)
This is a regression because the old list in the sidebar was visible while editing. (Compare with &useskinversion=1)
Editors ask for this functionality to be maintained. Request 1, request 2
- Explore adding functionality that adds language switching to the editing mode - this can use the existing language button or a different mechanism