I can't seem to reproduce this.
To make sure I understand it right: I'm in English language and select lang.account.php, make some edits and save it. I simply change language to Spanish, the same file is still selected and loads spanish definitions. I edit the file and save it, and it saves to the correct location (Successfully saved 1 overrides to includes/languages/spanish/responsive_classic/lang.account.php)
But yes, there might be issues with languages other than english because the plugin was originally built for a client who only wanted one language to edit, the rest was done just to try and accommodate it for the whole community... Please bear with me and help me iron it all out.
