When assigning a certain content template to a single CPT, pls add the option to remove the 'container' wrapped around the post content. Similar to what toolset already implemented for WC Product CPT -> "Add a container DIV around the post body for WooCommerce styling".
Instead of css overriding hack to make it full width, the option to remove/add a container DIV makes things less messy.
Views Content Templates don't add a wrapper div, they just output whatever is in the template directly. Whatever "wrapper" you find on the content comes from the theme. (That is easier to see when you are not using Divi—which adds *lots* of nested divs—and just add a simple Content Template with twentyseventeen, for example.)
In particular, the section Additionally, within the Row Settings set a custom width of “100%”. Do not select “Full-width row” because, despite the name, it sets the row width to “89%”.