Hey, thanks for reaching out :)
While nobody specifically asked me this before, I figured that the components I developed might be handy for an in-game level editor too, although major adaptions would have to be made. Since the editor has a similar structure as a Godot game (scene tree, process() functions, input events), re-purposing at least some parts of the tool would certainly be possible. However, all the plugin logic that ties into the EditorInterface, for example, would need to be stripped out, so you will have to dive into the plugin's code base quite deeply for integrating it into an in-game level editor.
Hope this helps, let me know if you have any specific questions about the source code and implementation.