That sounds like the right way to do it, but I'm a little bit afraid of trusting the file modification dates on Windows, so it would be useful to expose that boolean parameter to force it to rebuild the catalog.

As an aside, the getCatalogedPathnames is pretty much required if you don't know the names of the paths in your file, but because of how long it takes, and the bugs in it's built in path filtering ability, I try to avoid it whenever possible.