Downing wants to test the portal waters and see if there is a place for him with a better chance to play this year. I have not spoken to him so the reasons could be many other than the coaches not recognizing his talent.
There are politics in football as well as many BYU players can attest, especially now with NIL and the transfer portal. Not sure why he is transfering but like I said, will not be surprised if he goes somewhere else and tears it up. I've been around football a long time as a player (receiver), coach, booster, and have a son now who plays college ball as a receiver. Unless his talent dropped post mission (which can happen) or he just wants to test the waters to see if he could get more playing time elsewhere, hate to lose him because he's a flat out baller.
But I guess we will see.