Maybe send up a "Rag sheet" from the members subordinates with the brag sheet in the PER file? It could be done survey style (rate conduct out f 5) or as some short answers to direct questions. We could do it as part of the PDR process rather than part of his evaluation if people are concerned about a disgruntled subordinate attempting to tank an evaluation. This would give the chain a better sense of how that person relates to their chain and give them time to adjust their behavior before the PER.There was a pilot program a while ago for a 360 evaluation on some contracted leadership development course; I got to fill one in for a former supervisor. Apparently they bundled it up, took the high/low points and provided him some feedback.
Some of the most useful feedback I ever got was early in my career as a SLt from some of the PO1s and the Chief, as well as one of the LCdrs that wasn't my boss. Allowed me to course correct some things and build on others, and IMHO a good example of how the general development system should work. Same idea as a 360 system except it had real and concrete results.
Personally a big fan of the concept though; there are more then a few people that got a CO tour that were disasters when their shitty behaviour was obvious as a two ringer to their peers/subordinates. Even outside of the PERs it would be useful for some of the development phases; when they had the ORO sea phase it was usually pretty obvious who you would never want to actually work for, and the same probably applies for ph 6 / AHOD tours.