[Zope] + in url /zope object name

I am running into the problem mentioned in: http://mail.zope.org/pipermail/zope/2003-October/141868.html I have "+" used in a directory name of some content generated outside zope that I want to upload. Preserving the directory name is necessary for the integrity of the data. Why is "+" a prohibited name for a zope object? As a solution Andy Mackay suggests modifying zope to allow "+" in a zope object name. Is there a downside to this?