I guess I'll start contributing to the offseason rabble and not just "I Miss my BBMB" ranting.
Siemian did some positive things in Denver, I watched most of the games, but I think the ceiling is really low. He's not a big guy, noodle arm, not very athletic, spotty accuracy, not great at reads. Yeah, he could continue to develop, but I just don't you've got an All Pro in the works . Kubiak was always great at getting the best out of QBs, and Siemian is no exception.
He did not have the running game or offensive line support that would aid a young QB, but he did have a defense that bailed out the offense numerous times and the best wide receiver duo in the league to throw to and didn't exactly torch any secondaries late in the season.