can't ride a netsplit to takeover and +m a huge channel IRL
Well, almost. Apparently, it has its own wikipedia article. https://en.wikipedia.org/wiki/Netsplit
But with modern nickname and channel services (Nickserv and Chanserv, mostly), and the very small IRC userbase, they certainly aren't as impactful as they once were.
I think it was some buggy Rockwell modem chips that did not require the delay between +++ and switching to command mode, but it has been some decades.
Most cheap modems seemed to ignore the required 1 second (IIRC) delay. Well-heeled users who could afford U.S. Robotics et al were safe, winmodem users were not.