Am I able to edit my custom html template, after adding a Klaviyo drag and drop section?

I have uploaded an HTML template into Klaviyo, and added Klaviyo drag and drop support to a specific section. 

I am using that template in an abandoned checkout flow. 

The drag and drop editable section works great, but now when I go to edit the content of that particular email, it defaults to the drag and drop editor, and I can’t seem to figure out how to edit the rest of my email using HTML.

Is there a way to edit my HTML after I have added drag and drop support (other than modifying the original template?)

Edit: Just to be clear, because I can’t edit the title, I actually want to edit the html of the email I’m using in a flow (that is based off of a custom template). Not the original  custom template itself.