All flood protection has now been integrated into one routine and this item is now available as "Limit CTCP replies" in the Flood dialog. The heuristics have changed slightly as well, allowing only a certain number of CTCP replies within a fixed time period, which offers much better protection.
I am not sure it would be possible to keep mIRC behaving in one way or another based on how each IRC network bases its bot-detection. The way mIRC behaves changes with almost every version, as features are tweaked, bugs are fixed, etc. It would be difficult even if I knew the specific heuristics that each network used.
