I won't dig it up again but I posted a handful of SS who were sometimes forced to play 2B, 3B or CF because I had a better SS prospect in my system. There wasn't any noticable difference in their development. One of them was
Hardball Dynasty – Fantasy Baseball Sim Games - Player Profile: Angel Hernandez. As you can see, he played less than half of his innings at SS in the minors. In the seasons where his glove took the biggest jumps(S13), he played CF the most.
Could he have been better had he played SS the entire time? Maybe. But the season his glove became SS-like, he was playing CF/3B for over 600 innings and SS less the 300.