Never mind, I guess Counter happens more often than I thought, though I can go a bunch of turns without seeing it sometimes. Though, the full burst was only 33-36k for me with the Warrior, my buffs were Focus II and Shiver +30% (Hatter's key). I kinda expected more, but it still seems good... Building the full burst requires a bit of waiting for your EP to get high enough as well, though that didn't seem that bad. I really do wonder how the dps checks out against the Sage stance...
The warrior does not need to worry about buffs, just build up your gauge, let your EP increase (this part benefits more from harder difficulty and dream stage; Pafukusu for example isn't good for this), use Focus at the right time, Hatter's key before Focus II or at the same time with Sprint, and other than that you'll just have to worry about making sure you can struggle at the right time to prevent a stance change. More straightforward than I initially thought.
Not sure about the the new photo features, I guess I'll find out later. With the little testing I've done, I've been quite successful at refusing stance changes with 2 keys + struggle, but not sure how much more than w/ just 2 keys, it's definitely not fool-proof, you can still be forced into a stance change that way.
Btw, does dream stage outside of the DLC affect the difficulty for the expansion too? I'd rather do all the battles at the highest difficulty that it can be.