I saw one segment (ESPN or NFLN - can't remember which) where they were talking about the concern of "cheap hits" on QB's running the read option after they hand off.
They said that if the QB starts moving backwards after the handoff (towards their own goal), they will be protected by the Refs. If the QB continues to try to carry out the fake and run forward, they are fair game. They showed several video clips to show the difference. Some of the read option QB's already understand this, and you could see them clearly giving themselves up after the handoff. They showed Kaep doing it in the second half of the Super Bowl on several plays, but he was still getting a good "push" (two hands to the chest) as a minimum on almost every one of his hand offs.
Not sure if this lowers the effectiveness of the play. Seems to me that if the QB is backpeddling the split second he completes the handoff, it will make it easier for the Defense to make a play.