Nice idea for a switch, but what so you think about using a most meta-field instead? For example, set a custom field called embed-hide-title to true to hide the title of the post in any parent posts? It would be a global change, so wherever that post is embedded, the title would be hidden. It might be possible to allow the same flag to be set on a parent post to hide all child post titles.
Version 1.3 began using <h2> for the post title.
In all versions, you can use CSS to add formatting to the post_title class.
As of Version 1.3.1, backticks are supported (using a ` before and after slug).
