Editing has to be done systematically: a professional beta read (Structural, Developmental editing) is done separately to Line editing (style, word choice, tone) and both are done before Copy editing (grammar, punctuation, spelling, typology, factual correctness). Indexing comes after all these, and Proofreading is done at the formatting stage, last of all.
It is not possible to do any of these types of editing simultaneously: so I cannnot do a professional beta read and a copy edit in the same piece of work. This is because after a beta read, you take the manusript back and decide which of my recommendations to implement. (There is no point in doing a Copy edit if you will be rewriting passages.)
You may choose to skip a Line edit if you are confident in your use of words and go straight to a Copy edit.
Everyone should have a Copy edit before publishing, because it is a function of being human that everyone needs a second pair of eyes to check for blind spots and finger fumbles.