True… but I know that as a new coach starting out in IQ (many years ago, now!), and then moving into VRC, I had a LOT of trouble giving useful feedback after a certain point - even though as my son’s coach, I was very invested in doing my best and learning what I needed to learn to support the team. There seemed to be very few resources available for an independent team coach to really know how best to help them fully develop into the “Expert” category in this area.
We were fortunate that the kids were able to do as well as they did even fairly early on, and this was largely due to a few specific tips from 2 or 3 very kind, helpful individuals who had done some judging over the years and the extensive on-line research the team did into both Vex notebooks and general better documentation work.
However, we often considered the judging room as “the big black box”, where notebooks go to either succeed or die (and the only way you know which yours did was if you got an award). The team I coached went to dozens of competitions over many years and often won Design (and occasionally Excellence, later on)… but often didn’t, as well, with the same notebook and the same kids - and we really often had absolutely no idea what distinguished the win days from the didn’t win days (for Design). That’s really not conducive to giving kids a solid game-plan on what needs to be changed in order to make their work be the best it can be within the guidelines that the judges are operating.
That said - by FAR the best thing that I did to help us all better understand the process and how to improve a notebook to the next level was volunteer as a judge. I truly, honestly, deeply wish that I had done that within the first or second year that I started coaching. If I had known how insanely useful the information I got from judging even 1 event would be, I would have just asked to volunteer at any local event my kids weren’t competing in (so that I could focus fully on the event and not have to worry about anything team-related, while they were all so young).
In fact, the absolute best advice I can give for teams wanting feedback regarding the judging process and tips on how to improve their notebook is to have an adult close to the team go and volunteer for judging at an event.
So, after all that… I guess I totally agree with @lacsap that it should be the mentors giving the feedback, I just think that the mentors should BE judges so that they can give better feedback (or there should be some sort of training camp / class for mentors to attend that is structured in a way to give them that knowledge).