Cannot changeXwiki document title ($doc.title) for Blog entry easilly

This issue is for Xwiki version 1.8 with new Blog application.

When title for new post in Blog is entered, it sets two titles (don't know why such design pattern is common in Xwiki):
$doc.title and title for BlogPostClass object. One is shown in breadcrumb, another as title in Blog views.
However in edit mode only title for BlogPostClass object can be changed. To change $doc.title one should open post in wiki editing mode and then should change title in Wiki editing form.

If there is some reason to use two titles, it should be changed that both titles are changed in blog edit form.
For previous version I used workaround to simply show another input field with $doc.title as a value.
Though ../xwiki/bin/edit/Blog/BlogCode now seems too advanced to tweak it correctly.