I disagree, at least partially. Obviously playing in those 2.5 games was a great experience for him. More importantly he showed the coaches he has the right mentality to be a successful QB in the NFL.....someday.
However do not dismiss the value of being on the team every day, going to meetings to improve his understanding of the game, taking snaps in practice, even if most of them are on the scout team. There is also value in the coaching and skill development in the individual and group drills. All those things that he'll be missing if he goes on IR this early.
Now SOME of that might be mitigated if he's allowed to go to meetings and watch practices. But I'm not sure that's the current policy of how the team handle a player who goes on IR. It's my understanding that they basically cease to exist for the team, except for their rehabilitation.
I like the thought that if JB is put on IR another roster spot is taken care of. HOWEVER I think I'd rather have him on the field this season, even if it's only to "carry a clipboard"