My main issue with Leidner is that he still takes far too many sacks which are completely unnecessary if he would only and simply just throw away the ball as opposed to taking the sack. That's a mental thing that quite a few quarterbacks struggle with from time to time, but Mitch is still doing so consistently, and we are a chain to chain offense which quite often lacks the ability to make up the yardage lost due to sacks being taken. And the majority of these sacks, it's not like he's trying to extend the play or anything, he just simply seems to mentally freeze up and hold the ball when under duress, either that or backpedal in desperation which ultimately ends up costing him even more yardage. It's got to become instinctual for a quarterback to get rid of the ball when facing a sack and the play is not there. Throw it at the feet of a receiver or a back, throw it out of bounds, just get rid of it rather than taking the loss of yards. Throw it away, and reset for the next down.
Some quarterbacks learn that with experience, while some never do, and some with exceptional talent even take that unfortunate trait all the way to the NFL (David Carr, Jake Plummer and Jon Kitna spring immediately to mind amongst many others, and that 'hold-the ball-itis' tendency ultimately ended up not only hurting his teams but dramatically shortening David Carr's career- 267 sacks taken in 94 NFL games, damn.). It's a mentality as well as a thought process, so you never know how that's going to work out for a young quarterback, if that's ever going to click and the light bulb come on for them. You've got to do it though. You cannot take avoidable sacks like that when the opportunity is there to simply throw the ball away. Some sacks are unavoidable, as when the protection immediately and catastrophically fails or there's a blindside pass-rusher coming, but it's the avoidable ones (when you're facing the rush, when you're seeing it coming, and you've got the time and opportunity to throw the ball away), those are the sacks taken which have to be eliminated. That's an error of cognition though rather than one of mechanics, so it is possible to learn to do it until that becomes instinctive in nature.
So that's my main frustration with Leidner right now, but hopefully he can get past that and just learn to do it.