Hi There,
Please check this guide: https://developer.wordpress.org/themes/basics/template-hierarchy/
By default in wordpress, for pages we have the option to choose a template we want to use for per page. For post, product or other custom post type, the structure is already set. on the post template.
This statement: I’m trying to get my custom post types to behave more like pages than posts is a little vague. In case you meant an option to select template for custom post types, that is not how it works for custom post type so it is not possible. On the other hand, if you just want custom post type to be fullwidth like hos No Container template for page works, it can be possible either by CSS or editing the templates of current custom post type. Please clarify.
The easiest way for you now to make your custom post type fullwidth is to adjust the structure size via CSS, Please share your custom post type URL so we can check.
@kevrossignon hope this applies for you too.