Translations documents used "on demand" do not work for the document title

I'm hesitating between bug and feature, consider the following usecase:

• I have an application, I make a translations document used "on demand"
• in a document of my application, I have, of course, the line

  $services.localization.use('document', 'MyApp.TranslationsDocument'))
  

• in the title of document, I use a key that is translated in this document

  $services.localization.render("mykey")

• the title will not be translated, I would want it to be, because otherwise it means that there is no way to use translations in titles with ondemand translations, I will need to add it on the whole wiki.