Trick or Treat Exchange

If someone gave you fic with a DNW, I'm sorry to hear that, but that happens in other exchanges too, ones without extra challenges. People post drawer fic or don't read closely or go ODAO, and I don't know how to fix that. Mandatory approved betas? Artifically small exchanges? A dozen mods who know more fandoms to read each fic carefully before the exchange goes live? If you have some ideas, let's talk about them.