If Kap wanted a job for this season to simply re-establish himself as an NFL player for a few months the Pats would be the perfect place. He could take Cody Kessler's place as the #3 QB and provide the Pats with a key element that they just don't have at this point. Someone who can run the scout team and give the defense a great simulation of all the mobile QB's the Pats will face the rest of the season.
If he were OK with THAT specific role, I'd sign him in a minute. The benefit he'd get from us is being in a place where he can get good coaching and rebuild the skills that may have eroded over the last 3 years. He can rehabilitate his name simply by being in this organization, like so many others. And then there is that possibility of getting a ring. Then he'd be much better prepared to be a FA going into 2020 with 3 months being on a team, and not just ANY team.
Sounds like a plan to me.