Custom summary option from the admin page?

Hi there!
I've recently started using Garv as my blogging platform, and so far, it meets most of my needs! One thing I couldn't figure out is adding a custom summary to my blog posts on the list page from the admin. Display my posts X characters is not ideal, I want to write custom intros for them. Am I missing something or that is not supported yet?

Would delimiter work? But keep in mind, this summary is also included in the main content