It should be possible to enter no-width optional breaks especially in the URL-field. If you have a reference (citation in a footnote) with a long URL like “See The United States Government Manual 2009/2010 (available at http://www.gpoaccess.gov/documents/all/texts/gmanual/browse-gm-09.html), 87”, the URL will not be hyphenated without no-width optional breaks. Of course one can enter them manually after having formatted the citations/bibliography, but they will be lost after a reformatting.
Thank you for your consideration
Martin