It was a good idea by the NCAA, but it has also become college football free agency now too.
Kids can play the first 4 games of the year and showcase what they have, and then transfer to a better school if they wish.
As for Purdy, you play the hot hand. If he keeps playing like he did yesterday, then there isn't even a question, you keep playing him and burn his RS, why wouldn't you?
Even if Kempt is able to come back, you still start Purdy if he's playing like yesterday, not even a question at all. Kempt is a great story, but he's very one dimensional. And you never sit a QB that is playing as well as Purdy is right now.... never.