I don't know how this will translate to BYU because Declo is a 2A school in Idaho and he played against what most would consider lower-tier athletes. 

I watched the championship game with Declo against West Side. Keegan Duncan clearly dominated the game. They say football is a team sport, but on the 2A level, he showed how he was singularly dominant to every other kid on that field. Every time they got to 3rd down, they would simply hand, pitch, or throw to Duncan and he converted roughly 75% of them. He has a rare mix of speed and strength that made it impossible for high school kids to stop him. I'm excited to see how he plays against collegiate athletes.