I have difficulty restraining myself to, say, proofreading when working with a manuscript, because I feel an obligation to point out structural and other changes that might improve the document’s chances of delivering effectively what its author wants to say. My goal at all times is to help the text become clearer and stronger without undercutting the author’s message or blurring their distinctive ‘voice’.
I live in Canada, but spent many decades in the United States, so can edit for either audience (‘lift’ or ‘elevator’; ‘colour’ or ‘color’).