I honestly wonder to what extent catcher framing will be diminished if we don't move to full robo-umps but just the appeal system. I bet you a lot of 0-0 strikes that someone like Kirk steals will still remain, but anything like a questionable 3-1 or 2-strike frame jobs will be significantly diminished, and while I don't recall exactly if count is factored into framing value, those are obviously the most important types of pitches that influence catcher framing. Conversely, a catcher that slaps at the ball - exceedingly rare in the modern game - low in the zone or at the borders is still going to be losing strikes even in an appeal system.