You should check out Courtney Campbell's tricks at http://hackslashmaster.blogspot.com/p/artifices-deceptions-index.html and in book form at https://www.amazon.com/dp/B08Y4FHLR6

I have many ideas for Castle Greyhawk style stangitude on my site at http://greyhawkonline.com/grodog/gh_castle.html (both from the original castle created by Gary and Rob, and for my own version), and I've reprinted two pieces from Knockspell Magazine at https://grodog.blogspot.com/2017/04/one-way-doors-variable-stairs-and.html and https://grodog.blogspot.com/2017/05/dungeon-strangitude-variations-on.html

Allan.