You can create a microworld and place an entity that has the effect attached to it. If you set "enable_renderer_file_watcher" : true in your user_settings.json (should be on the same indentation level as “enable_analytics”), it will automatically update changes made in .cubemitter files (as you save the file). Change in the other effect.json files will require you to reload the microworld though.
I would also recommend using SHED if you are editting cubemitter or animatedlight files, as it gives you a template to work with. It’s under the Effects Editor tab page.
Let me know if you have any questions!
- Linda