Why on Earth would you want to protect a claimed miller? There is no reason for this. There are two ways that ABR could be killed. By scum, or by a vig. He's not going to be killed by scum, independent of the veracity of his claim, because millers are policy-lynched or vig'ed before LYLO. So you're not protecting ABR against a scum kill. You could only protect him from a VIG. A pro-town role trying to save us from the uninformative chore of lynching ABR before LYLO. However, ABR might have been investigated by a tracker. If he carried out the kill (admittedly, only a retarded scum group would have the kill carried out by their claimed miller), then thanks to you, the tracker would get 'no result.'
Yeah, what are the chances that a scumgroup is going to have their fake miller carry out a kill on Day 1, when there's a chance of a tracker roaming around?
The tracker, if we have one, is going to track ABR as his/her top priority. Why would you do that?