Google shouldn't even be seeing this board as a "dynamic" site anyhow. The trick that UBBThreads did is made it look like the site has a ton of static content across a lot of directories. And they did this in a clever way. If you take a URL like the one to read this thread:
http://empegbbs.com/ubbthreads/showflat.php/Cat/0/Number/283367/an/0/page/0

It makes it look like a folder structure by allowing variables to be passed in via / instead fo the normal & and ?. By default, the board will use that as the URLs for everything, unless it is a true dynamic area like the make a reply section.

Sadly if Google is going to yank the boards out just because I don't touch their sitemap or whatever (I made one once), then honestly it is not worth my time to ensure the boards are listed there. A webmaster shouldn't have to work to keep his search results coming back the same way they once did.