Creating customized blogs with CMS

I have been working on creating a customized blog setup using CMS and dynamic pages, as per this page . Ignoring the suggestion on that page that you can only have basic text, I used Rich Content to ensure that all images, video etc, from the blog could be displayed as it was written in the backend.

What I wanted to know was this. Is there any way of adding a subheading that stands alone without creating a new collection that was mine rather than a dedicated Wix collection? I would sooner keep using the backend system to create blog posts. I know I could reference these in a new collection and add a standalone subheading within that, but that seems convoluted, and I’m also not sure if it would hurt the SEO features that come with a blog.

What I’m trying to achieve is this:

Between the heading (in this case, ‘Burner Article 2’) and the featured image (displayed), I would like to have a subheading of around 50 characters that gave context to the article and could be referenced on other pages (home page, category page etc). I would then like the body of the article to appear below the header image, as it currently does, in Rich Content format.

Any help to clear up my roundabout explanation is very welcome!