I have no clue what we ultimately do but I agree he checks off a number of boxes. He would be our version of Wes Welker who can run the ball as well. He instantly fill a bunch of needs. I still like Howard at 8 but if he isn't there McCaffrey would instantly improve the offense.
But that's why we have Stewart. McCaffrey Is just a multi tool that we can utilize in the passing game. It's a bonus, he has all season to bulk up and gain strength with his awesome cast of NFL trainers that'll make sure that 10 rep bench will turn into a 20 rep bench by the end of the season.