Can you bring back Chaos Knight in second location? maybe make him optional like Fizzy if difficulty was the problem
It's not the difficulty level, but rather that you can't fight him unless you meet the specs, and you can't progress, so he's treated as a boss unrelated to the main scenario.
You can fight him in Junk Faure, so try looking for him.
do you plan on reworking Kirisaki then? Hes a pretty lackluster boss because of his lack of vore attacks.
Your game is great though!