It shouldn't be a problem
He might need to edit code then restart the server to do it, but the change should be fairly easy.
In [link|http://z.iwethey.org/forums/render/content/show?contentid=1069|this description] he said that it was the functional code he used. However the design of that code reduces all of your tags and valid attributes to a small configuration section, edit that and away you go. In fact the way that code was designed it would be possible for different users to say they wanted different parsing shortcuts available or not, and it would work. Just throw the appropriate group of things into that configuration before you start parsing the post.
So he definitely is able to add a few more tags. Now whether he has time to do so is another story entirely...
Cheers,
Ben
