KF can stay as long as he wants, as far as I'm concerned. He's getting pretty close to earning that status IMHO, if not already.
KF has already won at Iowa, and when players transfer out of his program its not because they dislike him. (at least there have been no reports of that). In fact, a Glenville QB that Iowa's recruiting recently said that he talked with Arvell Nelson and Arvell had nothing but good things to say about Iowa.
Thats saying something, considering Arvell was kicked off the team.