When creating a new Blog post (whether manually or through importing from RSS) the new page is created as full width.
At the bottom of each post the following setting is shown:
Page Fullwidth Content – On
(Remove container from page and show page content from left of the screen to the right)

I have to manually change this to “Off” in order for the post to be correctly displayed as full width header, but using the container for content.
How can I set this as the automatic default for new blog posts, without affecting podcast posts or pages?