Ok, this is now fixed once and for all! I've confirmed TinyMCE, CodeMirror, and JCE all work with multiple saves and cancels over and over again. I had to implement forcing the editor to update on store. I'm guessing JCE is listening to a specific event for its save behavior, but I'm not sure what that event is and forcing the update triggers it. Please update and let me know if you have any further issues.