i dont know how it makes no sense.
quite simple, if you think your ip is flagged, create a new account. if the new accounts get banned instantly, you'll know your ip is flagged.
if nothing happens you know you're fine.
also, you can't get your ip flagged when you get banned on your main for botting/macroing. this never really happend.
you can get your ip flagged by jagex when you get caught gold farming or RWT. but this is not always the case. in my and in many others opinion/experience.