Switching default extension: Why so hard?

I use Dreamweaver MX 2004 for Macintosh, and work in a collaborative
environment where at least of our clients want files saved with an .htm
extension and half want .html. Other than manually re-entering the extension
when I create a page or changing the XML document, is there an easier way to
toggle between these?

While we're on the subject, why doesn't Dreamweaver offer a simple check box
to deal with this default option? If there's an operational advantage in
requiring users to hack the XML, I'm unaware of it.