The problem is this question falls into the how do you tell someone their spouse is having an affair type question.
How receptive is the venue going to be to the information? Do they care more about the quality of presentation for maintaining a long term healthy bottom line or they out for the quick buck? Are they going to listen and care or are they going to write off your concerns as sour grapes? As heartless as it sounds, which will benefit your personal reputation with the vendor? I know that you care about those who want to be authors and want to do the best for them, but in this case that is best served by doing what is best for your long term reputation with the venue. I hope that helps.