You want to be sure the content is as good as it can be before you have the text copyedited.
I can conduct a manuscript assessment, looking at plot, characters, setting, pace, dialogue, point of view, suitability of the language and terminology for the genre and target audience, structure, theme, beginnings and endings, and any other aspects that contribute to the overall quality of the work.
I do not intervene in your manuscript at this point. Instead, you receive a report outlining the main findings in a constructive way, to guide you as you revise the text. You, as the author, remain in control. You might need to revise your manuscript a couple of times before you are happy with the text. Once you are finished, the copyediting can begin.