[User Select Language]
1) save the language selection not only in the cookie, but also in the settings profile, so that the user who logged in from another browser does not choose a language when logging in to their profile.
Naturally the site would load the settings when logging in and automatically set the selected language.
2) Maybe make check user request headers and auto install languages for this headers.
Yes please. I think this would also work on private tabs in browsers.