I'd certainly be open to try it, but McDonagh, like Staal, looks incredibly uncomfortable handling the puck on the point, they have so much poise in one end of the ice, and none on the other end. Both can rush the puck like pros though, weirdest thing.
MDZ and Stralman (to some degree) are the only defenseman on the team that have any clue on what to do with the puck on the point. Steve Eminger is capable as well because he uses a 3 foot stick.
McDonagh has a great shot, and his skating opens a lot of offensive opportunities, but him on the point should be near a last resort (as if we're not on that yet).