With my Casual Mode playthrough complete, on to Hard Mode!
Dungeon 1 was trickier, possibly just because of the level cap? At first my girls were basically doing no damage because they were weak noobs, then they were doing basically no damage because of the shame and nudity debuffs. There was allegedly 'no shortcut', but I still found it straightforward to sneak through to the boss, probably because I'm forgetting a handy shortcut that appeared in Casual mode. No, the problem was getting to the boss and then being able to deal any significant damage. I tried putting the Rags on Madoka (oops no, that was the cursed version), and so went with Sayaka instead, hoping to scale Sharpen while everyone else threw down debuffs; that didn't work, because of the defence buff the boss's minion uses; four sharpens later she was dealing like 4 damage a hit, which was not enough for that level of effort. Instead, it wound up being Kyouko with Fire Spear for the win; between Flaunt and Ribbon Tie, she could get 8 a hit from rotation 3, and wouldn't be stunned thanks to wearing the Rags. Not an easy win (she was last girl standing with only a few HP), but still a win.
With Madoka being in the cursed gown, she wasn't able to get enough Shame or Grovel for titles. Fortunately, the gown was removed on reentry, so I was able to use dungeon items to purge her Shamelessness and grind out the titles. 20 fights later, she'd been maxed out, and I could face the boss to get that last title. Those title stats will be a lot more important in this run, for sure!
Dungeon 2 was a significant pain even in Casual; in Hard Mode, with no way of escaping from corsets and heels, it was worse. Beyond a little bit of initial sneaking around to grab boxes before getting too debuffed, there really wasn't anything to do but to grind the first fight repeatedly until everyone learned how to deal with it. When everyone in the party is that debuffed and limited to a single weak random strike, you have to take the fight you can win. Once you're finished with the posture grind, there's not much threat left in the dungeon, but it really was quite a grind. The boss's posture checks are hard enough to occasionally catch out even fully-trained girls, but assuming you've done all the training before facing them, they're still not much of a threat once debuffed. With foreknowledge, there wasn't anything hard here, just a tedious grind to reach that conclusion.
I did notice that the boss lever was moved, so that you can't open the easy way to the boss before beating them, but it hardly mattered; you're almost certainly not making it across the room to get there in the first place until all your girls are fully-trained. Without any access to Happy Pills, I had a bit more difficulty getting Madoka to max Selfworth once I'd moved on to title grinding, since she'd apparently gone negative at some point. It wasn't a huge deal, though; she was barely into positives by the time I had my second girl maxed.