After a few days of using, one final thought... It would be really cool to have this as a standalone app, in addition to the plugin version. That way I wouldn't have to import to Calibre for the sole purpose of doing the conversion. Already using mobi-unpack and certain other to-remain-nameless tools that way.
Maybe if you don't feel like adding that, I'll work on doing it myself after I learn enough python to be dangerous.