I would let S&W just send you a new one. Send them a Email with the picture and they will send you a new one. I had the white dot fall out of my front sight, sent Email to S&W and the only response that I got and needed was they were sending me a new sight right out.
I think I would probably shoot the gun just the way it is. I don't think it would hurt anything but I am not sure. Some one else can probably advise better than me on that subject. I am still learning about my M&P only had mine 2 weeks now.
Good Luck