So lately, I've been playing BerserkRL, bits at a time, for months, maybe a few levels a day, and I finally got to see what happens if you reach Ironman level 100! :D The game tolerates you going over 100, but if you try to load the game when you're above 100, it instantly crashes. Attached, is the log file from my last run, and a screenshot of my stats screen on the last playable level. :)
It was still having the issue of crashing consistently when late-game Demons appear, but every once in a while, a Demon was able to spawn without it crashing. I don't know what was different on those occasions, but I did take a screenshot of the last Demon that was able to spawn properly, which happened a few levels before the end. :)
EDIT: Also, I just confirmed that it now crashes consistently when it gets to the trait selection screen. I can still upgrade my stats, though, and it gives me an extra point each time I reload, so I can boost my strength, dexterity, endurance, and willpower as much as I like! :D (I just can't do anything with them) :P