Fundamental improvements to file management are on the way in 5.5. FileMgrCache.xml will soon be a thing of the past.
If anyone is interested in helping,
we are looking for a handful of DToolsProjects50 and DToolsUsers50 databases from customers (from your SQL server) to run it through its paces internally before it gets to a beta group.
I will post instructions on how to do this in a couple of days - the basic instructions are to backup the databases, compress the backups to a zip file, and email to
beta@d-tools.com.
Until 5.5 comes out, fryeguy is right - it's best not to mess with this.