That's a big roll of the dice for me. We don't have a lot of info day 1, so if we somehow get a scum, it'll be a huge win, but if we get a townie, or worse, the Miller (giving us a false sense of security), it's kind of game over.
Though it does increase the odds for the cop and doctor to do good work (assuming we don't lynch them)
Someone would have to be VERY sure of their read, because it could end even worse.
Let's say we decide KY is the scum, vote on him, but he says no no I'm the cop! We decide not to risk it, so we either nolynch or vote for someone else. If we nolynch, we're back in the same situation and our cop might be dead to a NK (if he isn't, he's scum so bonus), if we vote someone else, scum would NK our cop and we could kill another townie.
I understand where you're comjng from with the extra day lynch information, but it seems really risky unless someone dramatically screams "I'm a scum, lynch me!"