Before I answer your question, I will ask one: Did you check the Interactive GPU caching system in SOuP ?
Just want to make sure you are not missing something that can be a much better solution compared to the frameCacher.
Now, back to your question:
A common solution for situations like this is a shelf button or something that sits on top of your assets, but is not part of the asset's dependency graph. So based on selection (any object in the scene), grab the namespaces, search for nodes of particular type within these namespaces and do something with them.