To prevent the blocked users from commenting on the media using the
buddyblock plugin, you will need to identify those blocked users and remove the comment-on-media area from rtMedia.
This is achievable with some custom coding. You can contact to the
buddyblock plugin developers for the block user's identification code. We can help you with the code which will be needed to remove the comment area.
Let us know the reply from the
buddyblock team so that we can assist you further.