Thanks for the links!
I've looked at how they're adding the context menus and it looks to be using an undocumented method, which came up once before:
Now that we've seen more than one example of this in the wild, we probably need to add support for it. I'm not sure when we'll do that, but we'll add it to our list.
(Note that you can create identical context menu items within Opus itself as a workaround, but only in Opus Pro unfortunately.)