Illo, I have a few suggestions to extend your plugins functionality that I think would not involve too much coding time:

1. Allow HTML editing and a media upload button (‘quicktags’ => true).
2. Enable for archives/category (maybe by adding a secondary input box per Post Type for archive & category listing)
3. Allow to remove/replace The Content instead of appending/preppending. Some plugins allow you to output info via shortocodes and this feature would give more flexibility. Could be done by a simple checkbox.

I think these improvement would increase the potential use scenarios of your plugin greatly. Also, I would be happy to provide you with the UI layout I have in mind of you consider to go ahead with these tweaks.

Thanks again for the plugin and for your time.