How do I combine Facebook social comments plug-in with comments on an Open Graph Action?

Question

Our FB app creates Actions that get sent to users' Friends via notifications.

Those friends can comment on the Action, within the notification on their Facebook feed.

Our app is also using Facebook comments social plug-in to allow people to comment on the "same" post within our app, with those comments associated with a url (as per the FB schema).

We obviously want to combine the facebook feed comments on the "Action" and our app's (FB social plug-in) comments into one, on our app.

The problem is that Actions do not have a URL we can associate the comments social plug-in to (and there is a bug, open from November, preventing a work around https://developers.facebook.com/bugs/164794086987157).

Any ideas on how to combine these two comment streams?

Thanks!