Curse Theme: Initially I thought that curse theme wouldn't work, but the status didn't feel crippling enough to prevent action. The player has to adapt to being afflicted with the status effect, which seems to add a more interesting game dynamic. The duration lasts long enough that players who bring curse resistance gear do still feel like they're getting a pay-off for it. Overall, curse theme feels pretty solid.
Split Status Theme: In terms of the statuses themselves, because fire is fairly uninteresting, you mostly only had to deal with the gameplay effects of shock. However, in terms of approaching the enemy groups, having the different attack patterns of shock and fire themed enemies did make things feel significantly fresher. Oilers and quicksilvers had different attack patterns, and fire puppy and shock puppy had different attack patterns, which made those groups more interesting to fight. However, the mech knights, retrodes, and scuttlebots were less interesting because their element was irrelevant.
Difficulty Feedback: Overall, the difficulty felt in line with what I had hoped we would see. Most of the fights had to be approached cautiously and tactically otherwise they would result in significant damage. There were some exceptions to this at points, but overall the difficulty felt well tuned for the level encounters.
For the boss battles, Ultimate Twins seemed to relatively too easy. The adds were too controllable and overall the difficulty wasn't improved enough over the original. There felt like there needed to be some other new element to increase the complexity and difficulty of the fight to make it a step above the current end-game. Ultimate Duke felt challenging enough, although phase 4 was a little overboard. Since this is only the test of difficulty and not the actual fight going live, I won't gripe about how Duke is still a heavily gunned favored fight that feels a little out of place with the rest of the game.