I think the problem is that - currently - the rendering and behaviour of the edit menu (which contains cut/copy/paste) is done within the app's runtime etc. So

I think the problem is that - currently - the rendering and behaviour of the edit menu (which contains cut/copy/paste) is done within the app's runtime etc. So there's no difference between an app directly retrieving data from the pasteboard and you hitting the paste button. The message about the app retrieving from the pasteboard still appears if you hit the paste button. It would likely need to be moved out to an IPC call to make this possible.