This would be incredibly helpful to have. As of right now, I created a separate clients group that is not a part of the proactive backup, called "_Terminated" and I move employees' clients into that group when they leave the company or we no longer need to backup the client pc. Problem is, even though I'm not creating new backup data, I cant easily get rid of the old data either.
And Lennert, you are absolutely correct about "not responding" for a looooong time.. Retrospect seems to do that for nearly every action requested of it.