Oh my! Two of my former theories got refuted today.
The more relevant one is about the subs. I just realized something: there are sometimes *different versions* of the same subdungeon.
Example: "Teeth Teeth Teeth" is found in the North, has the Strange Amulet, and a signpost with a horror story tweet with TEETH (of all!

). Then there's "Strange Amulet", found in the south, has the Strange Amulet, and a very different signpost about pulling back south against adversity. Different tile set, same items (signpost, 5 gold, amulet), different signpost story.
Also, the Dented Helmet is found in two different subs - with very different texts - whether found in North or Center. I think the list will go on and on as we realized just how deep the rabbit hole goes!
(the other theory was that it is practically impossible to get drunk drinking only tequilas, though that one's less relevant here...

)
"Thinker", just without the "ache".