As said, I have had instances of battles locking up and becoming unresponsive (though the game is still running) as well as the battle ending before all enemies have been killed. I have a gut feeling it might be related to faster enemy deaths or faster combat animations but I cannot be sure. Edit: Repeatable lock when Midgar Zolom/Midgardsormr blows a party member away. Edit2: Can confirm it's one of either faster battle, faster numbers or faster deaths.
In addition, Aerith in the red dress and Sephiroth with the book/attacking the reactor are reverting to the default lego models. I apologise for a lack of definite information.