Franks is what he is: a limited QB that Dan Mullen is going to adapt his offense around. Dan Mullen has notified the spread option/ zone read offense to existing talent as OC at Utah, OC at Florida and HC/OC at Mississippi State on a few occasions: 2004 Alex Smith and Brian Johnson, 2005 Chris Leak and Josh Portis, 2006 Chris Leak and Tim Tebow, 2009 Tyson Lee and Chris Relf, and 2012 Tyler Russell and Dak Prescott. This year it is Feleipe Franks and Kadarius Toney. In those transition years that I mentioned, Mullen has limited his spread option zone read (SOZR) playbook and given some of those plays to another player--a backup QB or a RB or WR who can run additional SOZR plays that the starting QB cannot run. Some of those limited QBs were actually good QBs, such as Alex Smith and Chris Leak, but they were limited different ways. Mullen finds those limitations and augments those abilities with another player. In some cases the athlete improves. Alex Smith improved from a 50% passer to a 65% passer and #1 NFL draft pick. Dak Prescott improved from 60% to 67%. Chris Leak remained at 62% completion at 8 yards per attempt, but his overall yardage dropped from 3,000 to 2,000. On the other hand, Tyson Lee and Tyler Russell peaked with Mullen as their coach and they found it hard to succeed anywhere else in the NFL or CFL.
Franks will remain a 55% passer, but under Mullen his yards per attempt have increased from 7 to 8 (Chris Leak level). Kadarius Toney adds almost 10 yards per attempt on the ground or in the air in those plays where Franks cannot execute. In "limited mode" Mullen's SOZR offense is basically everyone else's RPO offense with new language and some option thrown in until athletes like Toney, Prescott, Relf, Portis, Johnson, and Tebow are thrown in. Some of those pocket/ RPO QBs remain as RPO QBs (Leak, Lee, and Russell), and some turn into SOZR QBs who can also run RPOs (Smith, Johnson, Tebow, Prescott).