This is a classic support thread, I’ll say that. People have been wanting this since the beginning. But my view is that I have yet to see an example of this that spans more than a few feeds.
But I agree, this is a nice to have. The other thread, Key Word Filtering VS "Training" Feature - #6 by Conrad_Hughes, has to come first. I’ll go ahead and add a ticket for this, since it’s something that might get done when I finally hire a backend dev.