translation for user menu (markup template): some doubts

I know I can change menu labels here

but this mean also that I have to do that 2 or more times if I have 2 or more sections, and also means that it will not be translated in any language if I use mirror method to translate sections

I tried to solve this by adding languague variables to my language files,

but it just seems that adding something like

Sort By="Ordina Per"

just doesn't work

which is strange because if I underatsnd well this line of code

<?php echo JText::_($markup->get('menu.menu_ordering_label', 'Sort By'))?>

the menu label is managed by label inserted in markup template settings, but it's also still a JText manageable via the language files