Before PM6 Plus gets too established please add plugin architecture to the roadmap.
Mark's request for a List view promoted me to post this. Plugins would allow third party developers to extend PM6 Plus. It's worked wonders for Adobe.
If you're referring to the third-party plugins for Lightroom, I'm not so sure that's a good idea. I found the quality of the plugins to be inconsistent -- some OK, some not so good. Their use seemed like a convoluted process to me.