The Maze Controller’s Guide section of the Mazes and Monsters manual contains a lot of advice, some of it sound, some of it very bad. Perhaps the worst piece of advice is
If a player is becoming uncomfortable, terrified, confused, or frenzied, DON’T BACK OFF! Keep on challenging the player by upping the stakes in the fantasy. Don’t let a player leave the fantasy until they solve their issue! If players can’t handle it, they will freak out, flake out, or drop out. These are acceptable losses! You can’t make an omelet without driving some people mad.
But hey, it doesn’t go much further than Dogs in the Vineyard.
Here’s a section of the manual about designing Mazes: