I'm trying to temper my expectations but it's hard. My one question left for Rattler was whether the staff thought he was ready to start. It was confirmed that the staff think he is ready by Underhill and then by DA naming him the starter.
You are right about the footwork and spacing. I also noticed that he gets the ball out on time and the receivers are not waiting for it or having to slow up to make the timing work. I also noticed that not only is he accurate, but he has good ball placement which means that he is hitting receivers, including check downs to RBs, in stride so they can get YAC.
I suspect it's the way he gets the ball out on time and the fact that he puts the ball where he needs to for the receivers to get YAC that made Kubiak think he was the fit for this offense. That along with the arm and off schedule throws. Underhill said that Kubiak is excited to design a game plan around Rattler and seeing those things, I can see why.
I'm sure he will struggle some Sunday and he might not have a good game, but I see the vision for him in this offense and he is a perfect fit.