For me, I do believe it wisest to play Keenum for the first 2 games.
Get the dust knocked off, let the team play to some of its strengths, and raise the chance of winning the first two games

Farmer does make a solid case as to why one let's the kid suit, and start.
I especially appreciate the circular moment of the northern cal kid coming onto the field in SF, and taking the ball.

But, I don't buy that success will come with that version. And wins outrank development in my book this season.

it's still very early in camp, and the youngster may show that he's got plenty of maturity to handle the job from the get go.
but, rare is the player that has that from day one.