I've come across an odd sort of bug.
When I add a symbol containing type to the result art of an existing plugin group, then Undo, Illustrator crashes.
The issue goes away if I edit the symbol to convert all type to paths.
I know for a fact there are lots of problems with text & kPluginArt. This stems from the fact that the plugin art API was written years before they injected what is now the AI text engine; they didn't really test the plugin art API after they did this, primarily I'm guessing because none of the base AI functionality uses it.