Split the edit window into two pieces so both are visible on the screen at the same time. This is similar to the two-edit window request, or new edit window. But I find the split screen works great for coding and would likely do so for editing as well. It would allow you to have the bit of text you're editing visible and also reference sections or outline notes from somewhere else in the document visible at the same time, without having to manage windows or require a lot more display real-estate.