Principles
Why review a document while it is being written?
Early review catches factual misunderstandings before they spread through the rest of the document.
Reviewing during drafting is useful when the client's facts affect the structure or conclusion. It shortens the loop between a question, an answer, and the expert's revision.
Review decisions, not every keystroke
The client does not need to watch continuously. The expert can ask the client to check a specific paragraph, and line markers and comments keep the discussion anchored to that place.
Pause when the issue needs separate advice
Not every disagreement should be solved inside a comment. If new facts change the scope, fee, legal risk, or professional conclusion, the expert should pause drafting and explain the decision before continuing.