the football team traditionally has. Bronco let KVN pretty much do whatever he wanted almost from day one because he knew KVN had that ability. He has created the entire offense around Taysom's elite abilities.
Ziggy was a weird case because, as many CBers seem to forget, he had no idea how to football when he first met Bronco. When Bronco did play him, however, he had him play everywhere all over the line and took full advantage of his unique abilities.
Other than that, I can't think of any one player at BYU who was so great his talents were better than the system.