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NOTE: While editing CU3ER project which is already embedded on published article all changes you make to CU3ER will be visible in that article after each Save of your CU3ER project.
HINT: If you are about to heavily edit CU3ER already embedded in article you might want to duplicate CU3ER project and make those changes within CU3ER copy. Once you are satisfied with results you can simply replace with newly created one.