No but throwing the ball, reps matter. It's a conflict with the coaches wanting to win, and ignoring the most important position, the quarterback. This is where Eberflus' naive purist philosophy gets in the way. "There are 22 players, 22 jobs to do. No one more important than the other-" and blah blah. The QB position will always be most important in modern NFL. Hiding that player will only leave you snakebitten later, when you're Super Bowl ready sans one important player (06 Bears anyone?)
This comes down to George McCaskey laying out his vision when he's hiring the new GM and head coach. If your most valuable asset is Fields, you tell your GM and coach "I don't care about winning right now, we need to make sure to get QB right", and find a coach to develop him. Otherwise wins are how Poles and Eberflus are evaluated, and they have an incentive in conflict with Justin Fields development (or any other QB's) . We went through this last year with Nagy resistant to starting Fields to begin the year, because it was a make or break year for him in the W-L column. Somehow the owner, gm, coach, and Fields have got to get on the same page, which is get with modern football and develop a Quarterback.
If you aren't able to, it's better to lose big trying, and get a very high draft pick until they come around. And if they never come around, use that high pick to get a QB.