“Does anyone else have something to contribute on this front?”
My limited opinion is that BPO’s are pretty pathetic. Formal appraisals at least back up numbers with some formal analysis and even comps. I have gone through the runaround with some asset managers regarding BPO’s they have for short sales I have been involved with. I literally have sent them comps I dug up along to back up my arguments. Similarly I have had the asset manager reference properties to me that were used as comps for the BPO and when I dug them up those properties were cancelleds or expireds.