Updating plugin group art inside of a symbol

I want to add one or more of my plugin's custom plugin group art objects to a symbol, then drag that symbol out of the Symbols panel to add other instances -- of course, requiring my plugin to manage the plugin group art.

Judging by the thumbnail in the Symbols panel, it's added OK, but when I drag an instance into a document, it appears empty, and my plugin group does not get an update message to redraw itself. I could manually tell each plugin group object to redraw, but I don't see any way to receive notification of symbols that need to update.

Is it practical or even possible for custom plugin group art to exist within a symbol in a document?