[boost] Should auto-props svn:need-lock be used for some file types?

Looking at http://svn.boost.org/trac/boost/wiki/BoostSubversion MIME Types and End-Of-Line Styles, I realized that svn:need-lock wasn't used at all. I've read http://blogs.open.collab.net/svn/2007/07/from-the-questi.html but am not sure if I think it should be used anywhere anyway. What is the reason for Boost not to use svn:need-lock for eg image files? /$