I think that a basic problem here has nothing to do with specific word editors, or with the technqiues on how they handle line justification.
I worked in a publishing company, starting in 1951, when all printing was done by "hot metal." In those days if the book was set by one method, the spacing was between words, but the other method placed the spacing between the letters. BOTH methods produced some very ugly lines.
Our solution was to add (or cut) an innocuous word. (You can't do this with an exact quote, but you CAN do it most of the time.) I was working with text books for elementary and high school pupils, so we had to be very careful that information was never changed, but we could manipulate the way the information was worded.
Also, we always sent first galleys to the authors to read, so if such a word change disturbed an author, we were able to go back to the original. But the word change process solved many an ugly line.
This technique is even easier on a computer, because you get instant feedback on the changes.
Sue