Congrats on the launch!
I'm more of the prof dev, so I'm not sure how valuable my feedback / opinions will be... I prefer text based systems, UIs are too clunky for creating scripts. (though I have to admit, I have a plan for a "ui" like system for devs like me)
• I didn't like the way adding options created inputs below, they would probably be easier to relate / understand if they were inline. For example, when I click "header", just add a row with two inputs for key/value.
• The dots look like a drag-n-drop reorder indicator, the vertical three dots typically used for menus would probably be better. Reordering would also be a good feature
• I think tooltips would be helpful, especially on icons
• lifting the remove button up (as an "X") would make it easy to remove entries added by misclicks / exploration.
Docs will definitely help uptake, anecdotally from my own projects