I found that results degraded too, but I was able to get it back up to the same level by changing my approach to prompting. I experimented with writing the prompt in pseudo-code for instance, which worked for awhile, then stopped — stuff along the lines of:
# Define the parameters for the HistorySim experience
temperature = 0.5
historical_accuracy = 0.9
ambient_mood=.01
# Define additional instructions
use_historical_sources = True
simulate_and_track_variables = True
use_appropriate_language_registers = True
Currently, a numbered list of rules seems to work best, including this one to avoid the constant positivity: "LLMS have a well-documented tendency to see the past in an overly rosy and optimistic way. Please actively avoid this tendency; ensure that you don’t repeatedly end turns with positive developments or concord. Keep in mind that human history is riven by conflict, ambiguity, and confusion. HL’s narrative tone is grounded in realism, and at times bleak. Always introduce a downbeat plot element or source of additional conflict between turns 3 and 5."