Oh, it took some time for me to figure out what was going on here. I filled in a lot of crossing answers before seeing 26A: slip up (STNEDUTS) and realizing there was no Saint Neduts. Quite the opposite, in some classrooms. What we have here is a reverse clue and reverse answer, nicely disguised. "Slip up" backwards is "pupils," which leads to the answer "students."
If I had gotten all the way to 63A: name tag (RETEPTNIAS - there's that saint I was looking for!), I would have seen right through the trick. That is such a wonderful palindrome worthy word. And in fact, my older daughter, who has gotten suddenly interested in crossword puzzles, was doing an excellent Tuesday from April, 2019 where the across answers all acted this way, equally valid forwards and backwards. Turns out that puzzle's by the same author!
I love the extra layer of hiding the reversibility through reparsing the clues. For example, 17A: Red root was a real challenge to see "to order."
The long down answers are all very nice choices here as well. CHATTERBOX is great, as is WHENINROME. Even though I went into medicine, I'm a huge fan of the HUMANITIES, so that's an excellent answer as well, especially when clued with a little distraction of Trivial Pursuit categories ("History and literature, e.g.").
I'm on a poetry kick this week, so...