Do you already have a way to generate the key points? Through a plugin maybe?
You’ll need a way first to create the summary section, then you can add those through a Hook Element or a Block Element.
It may be good to ask for suggestions for such a plugin here: https://www.facebook.com/groups/1113359788719597
Alternatively, if you plan to create these manually per post. You can use Advanced custom fields plugin to create a custom field for that.
Then, you can try to retrieve it through a GB Headline Block.