but in asset admin, the translated value is set

Yea, _t only falls back to the config variable if the translation doesn't exist

Ugh, apparently has to be done in a translation file

but the CMS Menu hasn't changed and LeftAndMain::MainMenu() returns "Files" as the title

Debuging LeftAndMain::menu_title() implies that the title is "Document Store"

  1. SilverStripe\AssetAdmin\Controller\AssetAdmin:
  2. menu_title: 'Document Store'

Also, anyone know why the following doesn't change AssetAdmin.menu_title?

Have you tried moving the whole method onto the Controller?

So hang on, you are calling renderWith on the Page or the Controller?